From 502f0ecc9ad5d4b89912ebe310d82366a9727105 Mon Sep 17 00:00:00 2001
From: Lantao Jin <ltjin@amazon.com>
Date: Wed, 6 Nov 2024 08:35:26 +0800
Subject: [PATCH 1/4] [followup] Refactor JSON function and add TO_JSON_STRING,
 ARRAY_LENGHT functions (#870)

Signed-off-by: Lantao Jin <ltjin@amazon.com>
---
 docs/ppl-lang/functions/ppl-json.md           | 73 +++++++++++++++----
 .../FlintSparkPPLJsonFunctionITSuite.scala    | 38 +++++-----
 .../src/main/antlr4/OpenSearchPPLLexer.g4     |  2 +
 .../src/main/antlr4/OpenSearchPPLParser.g4    |  2 +
 .../function/BuiltinFunctionName.java         |  2 +
 .../ppl/utils/BuiltinFunctionTransformer.java | 22 ++----
 ...PlanJsonFunctionsTranslatorTestSuite.scala | 20 +++--
 7 files changed, 100 insertions(+), 59 deletions(-)

diff --git a/docs/ppl-lang/functions/ppl-json.md b/docs/ppl-lang/functions/ppl-json.md
index 1953e8c70..5b26ee427 100644
--- a/docs/ppl-lang/functions/ppl-json.md
+++ b/docs/ppl-lang/functions/ppl-json.md
@@ -4,11 +4,11 @@
 
 **Description**
 
-`json(value)` Evaluates whether a value can be parsed as JSON. Returns the json string if valid, null otherwise.
+`json(value)` Evaluates whether a string can be parsed as JSON format. Returns the string value if valid, null otherwise.
 
-**Argument type:** STRING/JSON_ARRAY/JSON_OBJECT
+**Argument type:** STRING
 
-**Return type:** STRING
+**Return type:** STRING/NULL
 
 A STRING expression of a valid JSON object format.
 
@@ -47,7 +47,7 @@ A StructType expression of a valid JSON object.
 
 Example:
 
-    os> source=people | eval result = json(json_object('key', 123.45)) | fields result
+    os> source=people | eval result = json_object('key', 123.45) | fields result
     fetched rows / total rows = 1/1
     +------------------+
     | result           |
@@ -55,7 +55,7 @@ Example:
     | {"key":123.45}   |
     +------------------+
 
-    os> source=people | eval result = json(json_object('outer', json_object('inner', 123.45))) | fields result
+    os> source=people | eval result = json_object('outer', json_object('inner', 123.45)) | fields result
     fetched rows / total rows = 1/1
     +------------------------------+
     | result                       |
@@ -81,13 +81,13 @@ Example:
 
     os> source=people | eval `json_array` = json_array(1, 2, 0, -1, 1.1, -0.11)
     fetched rows / total rows = 1/1
-    +----------------------------+
-    | json_array                 |
-    +----------------------------+
-    | 1.0,2.0,0.0,-1.0,1.1,-0.11 |
-    +----------------------------+
+    +------------------------------+
+    | json_array                   |
+    +------------------------------+
+    | [1.0,2.0,0.0,-1.0,1.1,-0.11] |
+    +------------------------------+
 
-    os> source=people | eval `json_array_object` = json(json_object("array", json_array(1, 2, 0, -1, 1.1, -0.11)))
+    os> source=people | eval `json_array_object` = json_object("array", json_array(1, 2, 0, -1, 1.1, -0.11))
     fetched rows / total rows = 1/1
     +----------------------------------------+
     | json_array_object                      |
@@ -95,15 +95,44 @@ Example:
     | {"array":[1.0,2.0,0.0,-1.0,1.1,-0.11]} |
     +----------------------------------------+
 
+### `TO_JSON_STRING`
+
+**Description**
+
+`to_json_string(jsonObject)` Returns a JSON string with a given json object value.
+
+**Argument type:** JSON_OBJECT (Spark StructType/ArrayType)
+
+**Return type:** STRING
+
+Example:
+
+    os> source=people | eval `json_string` = to_json_string(json_array(1, 2, 0, -1, 1.1, -0.11)) | fields json_string
+    fetched rows / total rows = 1/1
+    +--------------------------------+
+    | json_string                    |
+    +--------------------------------+
+    | [1.0,2.0,0.0,-1.0,1.1,-0.11]   |
+    +--------------------------------+
+
+    os> source=people | eval `json_string` = to_json_string(json_object('key', 123.45)) | fields json_string
+    fetched rows / total rows = 1/1
+    +-----------------+
+    | json_string     |
+    +-----------------+
+    | {'key', 123.45} |
+    +-----------------+
+
+
 ### `JSON_ARRAY_LENGTH`
 
 **Description**
 
-`json_array_length(jsonArray)` Returns the number of elements in the outermost JSON array.
+`json_array_length(jsonArrayString)` Returns the number of elements in the outermost JSON array string.
 
-**Argument type:** STRING/JSON_ARRAY
+**Argument type:** STRING
 
-A STRING expression of a valid JSON array format, or JSON_ARRAY object.
+A STRING expression of a valid JSON array format.
 
 **Return type:** INTEGER
 
@@ -119,6 +148,21 @@ Example:
     | 4         | 5         | null        |
     +-----------+-----------+-------------+
 
+
+### `ARRAY_LENGTH`
+
+**Description**
+
+`array_length(jsonArray)` Returns the number of elements in the outermost array.
+
+**Argument type:** ARRAY
+
+ARRAY or JSON_ARRAY object.
+
+**Return type:** INTEGER
+
+Example:
+
     os> source=people | eval `json_array` = json_array_length(json_array(1,2,3,4)), `empty_array` = json_array_length(json_array())
     fetched rows / total rows = 1/1
     +--------------+---------------+
@@ -127,6 +171,7 @@ Example:
     | 4            | 0             |
     +--------------+---------------+
 
+
 ### `JSON_EXTRACT`
 
 **Description**
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJsonFunctionITSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJsonFunctionITSuite.scala
index 7cc0a221d..fca758101 100644
--- a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJsonFunctionITSuite.scala
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJsonFunctionITSuite.scala
@@ -163,30 +163,32 @@ class FlintSparkPPLJsonFunctionITSuite
     assert(ex.getMessage().contains("should all be the same type"))
   }
 
-  test("test json_array() with json()") {
+  test("test json_array() with to_json_tring()") {
     val frame = sql(s"""
-                       | source = $testTable | eval result = json(json_array(1,2,0,-1,1.1,-0.11)) | head 1 | fields result
+                       | source = $testTable | eval result = to_json_string(json_array(1,2,0,-1,1.1,-0.11)) | head 1 | fields result
                        | """.stripMargin)
     assertSameRows(Seq(Row("""[1.0,2.0,0.0,-1.0,1.1,-0.11]""")), frame)
   }
 
-  test("test json_array_length()") {
+  test("test array_length()") {
     var frame = sql(s"""
-                   | source = $testTable | eval result = json_array_length(json_array('this', 'is', 'a', 'string', 'array')) | head 1 | fields result
-                   | """.stripMargin)
+         | source = $testTable| eval result = array_length(json_array('this', 'is', 'a', 'string', 'array')) | head 1 | fields result
+         | """.stripMargin)
     assertSameRows(Seq(Row(5)), frame)
 
     frame = sql(s"""
-                   | source = $testTable | eval result = json_array_length(json_array(1, 2, 0, -1, 1.1, -0.11)) | head 1 | fields result
-                   | """.stripMargin)
+         | source = $testTable| eval result = array_length(json_array(1, 2, 0, -1, 1.1, -0.11)) | head 1 | fields result
+         | """.stripMargin)
     assertSameRows(Seq(Row(6)), frame)
 
     frame = sql(s"""
-                   | source = $testTable | eval result = json_array_length(json_array()) | head 1 | fields result
-                   | """.stripMargin)
+         | source = $testTable| eval result = array_length(json_array()) | head 1 | fields result
+         | """.stripMargin)
     assertSameRows(Seq(Row(0)), frame)
+  }
 
-    frame = sql(s"""
+  test("test json_array_length()") {
+    var frame = sql(s"""
                    | source = $testTable | eval result = json_array_length('[]') | head 1 | fields result
                    | """.stripMargin)
     assertSameRows(Seq(Row(0)), frame)
@@ -211,24 +213,24 @@ class FlintSparkPPLJsonFunctionITSuite
   test("test json_object()") {
     // test value is a string
     var frame = sql(s"""
-         | source = $testTable| eval result = json(json_object('key', 'string_value')) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object('key', 'string_value')) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"key":"string_value"}""")), frame)
 
     // test value is a number
     frame = sql(s"""
-         | source = $testTable| eval result = json(json_object('key', 123.45)) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object('key', 123.45)) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"key":123.45}""")), frame)
 
     // test value is a boolean
     frame = sql(s"""
-         | source = $testTable| eval result = json(json_object('key', true)) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object('key', true)) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"key":true}""")), frame)
 
     frame = sql(s"""
-         | source = $testTable| eval result = json(json_object("a", 1, "b", 2, "c", 3)) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object("a", 1, "b", 2, "c", 3)) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"a":1,"b":2,"c":3}""")), frame)
   }
@@ -236,13 +238,13 @@ class FlintSparkPPLJsonFunctionITSuite
   test("test json_object() and json_array()") {
     // test value is an empty array
     var frame = sql(s"""
-         | source = $testTable| eval result = json(json_object('key', array())) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object('key', array())) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"key":[]}""")), frame)
 
     // test value is an array
     frame = sql(s"""
-         | source = $testTable| eval result = json(json_object('key', array(1, 2, 3))) | head 1 | fields result
+         | source = $testTable| eval result = to_json_string(json_object('key', array(1, 2, 3))) | head 1 | fields result
          | """.stripMargin)
     assertSameRows(Seq(Row("""{"key":[1,2,3]}""")), frame)
 
@@ -272,14 +274,14 @@ class FlintSparkPPLJsonFunctionITSuite
 
   test("test json_object() nested") {
     val frame = sql(s"""
-                   | source = $testTable | eval result = json(json_object('outer', json_object('inner', 123.45))) | head 1 | fields result
+                   | source = $testTable | eval result = to_json_string(json_object('outer', json_object('inner', 123.45))) | head 1 | fields result
                    | """.stripMargin)
     assertSameRows(Seq(Row("""{"outer":{"inner":123.45}}""")), frame)
   }
 
   test("test json_object(), json_array() and json()") {
     val frame = sql(s"""
-                       | source = $testTable | eval result = json(json_object("array", json_array(1,2,0,-1,1.1,-0.11))) | head 1 | fields result
+                       | source = $testTable | eval result = to_json_string(json_object("array", json_array(1,2,0,-1,1.1,-0.11))) | head 1 | fields result
                        | """.stripMargin)
     assertSameRows(Seq(Row("""{"array":[1.0,2.0,0.0,-1.0,1.1,-0.11]}""")), frame)
   }
diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
index fcec4d13f..93efb2df1 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
@@ -378,6 +378,7 @@ JSON:                               'JSON';
 JSON_OBJECT:                        'JSON_OBJECT';
 JSON_ARRAY:                         'JSON_ARRAY';
 JSON_ARRAY_LENGTH:                  'JSON_ARRAY_LENGTH';
+TO_JSON_STRING:                     'TO_JSON_STRING';
 JSON_EXTRACT:                       'JSON_EXTRACT';
 JSON_KEYS:                          'JSON_KEYS';
 JSON_VALID:                         'JSON_VALID';
@@ -393,6 +394,7 @@ JSON_VALID:                         'JSON_VALID';
 
 // COLLECTION FUNCTIONS
 ARRAY:                              'ARRAY';
+ARRAY_LENGTH:                       'ARRAY_LENGTH';
 
 // LAMBDA FUNCTIONS
 //EXISTS:                             'EXISTS';
diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
index b7f293a4a..06dffa55c 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
@@ -860,6 +860,7 @@ jsonFunctionName
    | JSON_OBJECT
    | JSON_ARRAY
    | JSON_ARRAY_LENGTH
+   | TO_JSON_STRING
    | JSON_EXTRACT
    | JSON_KEYS
    | JSON_VALID
@@ -876,6 +877,7 @@ jsonFunctionName
 
 collectionFunctionName
    : ARRAY
+   | ARRAY_LENGTH
    ;
 
 lambdaFunctionName
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
index 13b5c20ef..1959d0f6d 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/expression/function/BuiltinFunctionName.java
@@ -213,6 +213,7 @@ public enum BuiltinFunctionName {
   JSON_OBJECT(FunctionName.of("json_object")),
   JSON_ARRAY(FunctionName.of("json_array")),
   JSON_ARRAY_LENGTH(FunctionName.of("json_array_length")),
+  TO_JSON_STRING(FunctionName.of("to_json_string")),
   JSON_EXTRACT(FunctionName.of("json_extract")),
   JSON_KEYS(FunctionName.of("json_keys")),
   JSON_VALID(FunctionName.of("json_valid")),
@@ -228,6 +229,7 @@ public enum BuiltinFunctionName {
 
   /** COLLECTION Functions **/
   ARRAY(FunctionName.of("array")),
+  ARRAY_LENGTH(FunctionName.of("array_length")),
 
   /** LAMBDA Functions **/
   ARRAY_FORALL(FunctionName.of("forall")),
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/utils/BuiltinFunctionTransformer.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/utils/BuiltinFunctionTransformer.java
index e39c9ab38..0b0fb8314 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/utils/BuiltinFunctionTransformer.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/utils/BuiltinFunctionTransformer.java
@@ -28,6 +28,7 @@
 
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ADD;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.ADDDATE;
+import static org.opensearch.sql.expression.function.BuiltinFunctionName.ARRAY_LENGTH;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.DATEDIFF;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.DATE_ADD;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.DATE_SUB;
@@ -58,6 +59,7 @@
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.SYSDATE;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.TIMESTAMPADD;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.TIMESTAMPDIFF;
+import static org.opensearch.sql.expression.function.BuiltinFunctionName.TO_JSON_STRING;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.TRIM;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.UTC_TIMESTAMP;
 import static org.opensearch.sql.expression.function.BuiltinFunctionName.WEEK;
@@ -102,7 +104,9 @@ public interface BuiltinFunctionTransformer {
             .put(COALESCE, "coalesce")
             .put(LENGTH, "length")
             .put(TRIM, "trim")
+            .put(ARRAY_LENGTH, "array_size")
             // json functions
+            .put(TO_JSON_STRING, "to_json")
             .put(JSON_KEYS, "json_object_keys")
             .put(JSON_EXTRACT, "get_json_object")
             .build();
@@ -126,26 +130,12 @@ public interface BuiltinFunctionTransformer {
         .put(
             JSON_ARRAY_LENGTH,
             args -> {
-                // Check if the input is an array (from json_array()) or a JSON string
-                if (args.get(0) instanceof UnresolvedFunction) {
-                    // Input is a JSON array
-                    return UnresolvedFunction$.MODULE$.apply("json_array_length",
-                        seq(UnresolvedFunction$.MODULE$.apply("to_json", seq(args), false)), false);
-                } else {
-                    // Input is a JSON string
-                    return UnresolvedFunction$.MODULE$.apply("json_array_length", seq(args.get(0)), false);
-                }
+                return UnresolvedFunction$.MODULE$.apply("json_array_length", seq(args.get(0)), false);
             })
         .put(
             JSON,
             args -> {
-                // Check if the input is a named_struct (from json_object()) or a JSON string
-                if (args.get(0) instanceof UnresolvedFunction) {
-                    return UnresolvedFunction$.MODULE$.apply("to_json", seq(args.get(0)), false);
-                } else {
-                    return UnresolvedFunction$.MODULE$.apply("get_json_object",
-                        seq(args.get(0), Literal$.MODULE$.apply("$")), false);
-                }
+                return UnresolvedFunction$.MODULE$.apply("get_json_object", seq(args.get(0), Literal$.MODULE$.apply("$")), false);
             })
         .put(
             JSON_VALID,
diff --git a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJsonFunctionsTranslatorTestSuite.scala b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJsonFunctionsTranslatorTestSuite.scala
index 216c0f232..6193bc43f 100644
--- a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJsonFunctionsTranslatorTestSuite.scala
+++ b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJsonFunctionsTranslatorTestSuite.scala
@@ -48,7 +48,7 @@ class PPLLogicalPlanJsonFunctionsTranslatorTestSuite
     val context = new CatalystPlanContext
     val logPlan =
       planTransformer.visit(
-        plan(pplParser, """source=t a = json(json_object('key', array(1, 2, 3)))"""),
+        plan(pplParser, """source=t a = to_json_string(json_object('key', array(1, 2, 3)))"""),
         context)
 
     val table = UnresolvedRelation(Seq("t"))
@@ -97,7 +97,9 @@ class PPLLogicalPlanJsonFunctionsTranslatorTestSuite
     val context = new CatalystPlanContext
     val logPlan =
       planTransformer.visit(
-        plan(pplParser, """source=t a = json(json_object('key', json_array(1, 2, 3)))"""),
+        plan(
+          pplParser,
+          """source=t a = to_json_string(json_object('key', json_array(1, 2, 3)))"""),
         context)
 
     val table = UnresolvedRelation(Seq("t"))
@@ -139,25 +141,21 @@ class PPLLogicalPlanJsonFunctionsTranslatorTestSuite
     comparePlans(expectedPlan, logPlan, false)
   }
 
-  test("test json_array_length(json_array())") {
+  test("test array_length(json_array())") {
     val context = new CatalystPlanContext
     val logPlan =
       planTransformer.visit(
-        plan(pplParser, """source=t a = json_array_length(json_array(1,2,3))"""),
+        plan(pplParser, """source=t a = array_length(json_array(1,2,3))"""),
         context)
 
     val table = UnresolvedRelation(Seq("t"))
     val jsonFunc =
       UnresolvedFunction(
-        "json_array_length",
+        "array_size",
         Seq(
           UnresolvedFunction(
-            "to_json",
-            Seq(
-              UnresolvedFunction(
-                "array",
-                Seq(Literal(1), Literal(2), Literal(3)),
-                isDistinct = false)),
+            "array",
+            Seq(Literal(1), Literal(2), Literal(3)),
             isDistinct = false)),
         isDistinct = false)
     val filterExpr = EqualTo(UnresolvedAttribute("a"), jsonFunc)

From cfd41a36a853f5b413fca7d03584bd1ba95e64bf Mon Sep 17 00:00:00 2001
From: Lantao Jin <ltjin@amazon.com>
Date: Wed, 6 Nov 2024 09:19:56 +0800
Subject: [PATCH 2/4] Join side aliases should be optional (#862)

* Join side aliases should be optional

Signed-off-by: Lantao Jin <ltjin@amazon.com>

* address comments

Signed-off-by: Lantao Jin <ltjin@amazon.com>

* typo

Signed-off-by: Lantao Jin <ltjin@amazon.com>

---------

Signed-off-by: Lantao Jin <ltjin@amazon.com>
---
 docs/ppl-lang/PPL-Example-Commands.md         |   6 +-
 docs/ppl-lang/ppl-join-command.md             |  23 +-
 .../spark/ppl/FlintSparkPPLBasicITSuite.scala |  64 ++++
 .../spark/ppl/FlintSparkPPLJoinITSuite.scala  | 269 +++++++++++++++-
 .../src/main/antlr4/OpenSearchPPLParser.g4    |   2 +-
 .../sql/ast/tree/DescribeRelation.java        |   4 +-
 .../org/opensearch/sql/ast/tree/Join.java     |   6 +-
 .../org/opensearch/sql/ast/tree/Relation.java |  41 +--
 .../sql/ast/tree/SubqueryAlias.java           |  10 +-
 .../sql/ppl/CatalystExpressionVisitor.java    |  10 +
 .../sql/ppl/CatalystPlanContext.java          |  60 ++--
 .../sql/ppl/CatalystQueryPlanVisitor.java     |   3 +-
 .../opensearch/sql/ppl/parser/AstBuilder.java |  28 +-
 ...lPlanBasicQueriesTranslatorTestSuite.scala |  40 ++-
 ...PLLogicalPlanJoinTranslatorTestSuite.scala | 292 +++++++++++++++++-
 15 files changed, 755 insertions(+), 103 deletions(-)

diff --git a/docs/ppl-lang/PPL-Example-Commands.md b/docs/ppl-lang/PPL-Example-Commands.md
index e780f688d..e80f8c906 100644
--- a/docs/ppl-lang/PPL-Example-Commands.md
+++ b/docs/ppl-lang/PPL-Example-Commands.md
@@ -306,7 +306,11 @@ source = table |  where ispresent(a) |
 - `source = table1 | left semi join left = l right = r on l.a = r.a table2`
 - `source = table1 | left anti join left = l right = r on l.a = r.a table2`
 - `source = table1 | join left = l right = r [ source = table2 | where d > 10 | head 5 ]`
-
+- `source = table1 | inner join on table1.a = table2.a table2 | fields table1.a, table2.a, table1.b, table1.c` (directly refer table name)
+- `source = table1 | inner join on a = c table2 | fields a, b, c, d` (ignore side aliases as long as no ambiguous)
+- `source = table1 as t1 | join left = l right = r on l.a = r.a table2 as t2 | fields l.a, r.a` (side alias overrides table alias)
+- `source = table1 as t1 | join left = l right = r on l.a = r.a table2 as t2 | fields t1.a, t2.a` (error, side alias overrides table alias)
+- `source = table1 | join left = l right = r on l.a = r.a [ source = table2 ] as s | fields l.a, s.a` (error, side alias overrides subquery alias)
 
 #### **Lookup**
 [See additional command details](ppl-lookup-command.md)
diff --git a/docs/ppl-lang/ppl-join-command.md b/docs/ppl-lang/ppl-join-command.md
index 525373f7c..b374bce5f 100644
--- a/docs/ppl-lang/ppl-join-command.md
+++ b/docs/ppl-lang/ppl-join-command.md
@@ -65,8 +65,8 @@ WHERE t1.serviceName = `order`
 SEARCH source=<left-table>
 | <other piped command>
 | [joinType] JOIN
-    leftAlias
-    rightAlias
+    [leftAlias]
+    [rightAlias]
     [joinHints]
     ON joinCriteria
     <right-table>
@@ -79,12 +79,12 @@ SEARCH source=<left-table>
 
 **leftAlias**
 - Syntax: `left = <leftAlias>`
-- Required
+- Optional
 - Description: The subquery alias to use with the left join side, to avoid ambiguous naming.
 
 **rightAlias**
 - Syntax: `right = <rightAlias>`
-- Required
+- Optional
 - Description: The subquery alias to use with the right join side, to avoid ambiguous naming.
 
 **joinHints**
@@ -138,11 +138,11 @@ Rewritten by PPL Join query:
 ```sql
 SEARCH source=customer
 | FIELDS c_custkey
-| LEFT OUTER JOIN left = c, right = o
-    ON c.c_custkey = o.o_custkey AND o_comment NOT LIKE '%unusual%packages%'
+| LEFT OUTER JOIN
+    ON c_custkey = o_custkey AND o_comment NOT LIKE '%unusual%packages%'
     orders
-| STATS count(o_orderkey) AS c_count BY c.c_custkey
-| STATS count(1) AS custdist BY c_count
+| STATS count(o_orderkey) AS c_count BY c_custkey
+| STATS count() AS custdist BY c_count
 | SORT - custdist, - c_count
 ```
 _- **Limitation: sub-searches is unsupported in join right side**_
@@ -151,14 +151,15 @@ If sub-searches is supported, above ppl query could be rewritten as:
 ```sql
 SEARCH source=customer
 | FIELDS c_custkey
-| LEFT OUTER JOIN left = c, right = o ON c.c_custkey = o.o_custkey
+| LEFT OUTER JOIN
+   ON c_custkey = o_custkey
    [
       SEARCH source=orders
       | WHERE o_comment NOT LIKE '%unusual%packages%'
       | FIELDS o_orderkey, o_custkey
    ]
-| STATS count(o_orderkey) AS c_count BY c.c_custkey
-| STATS count(1) AS custdist BY c_count
+| STATS count(o_orderkey) AS c_count BY c_custkey
+| STATS count() AS custdist BY c_count
 | SORT - custdist, - c_count
 ```
 
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLBasicITSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLBasicITSuite.scala
index cbc4308b0..3bd98edf1 100644
--- a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLBasicITSuite.scala
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLBasicITSuite.scala
@@ -597,4 +597,68 @@ class FlintSparkPPLBasicITSuite
           | """.stripMargin))
     assert(ex.getMessage().contains("Invalid table name"))
   }
+
+  test("Search multiple tables - translated into union call with fields") {
+    val frame = sql(s"""
+                       | source = $t1, $t2
+                       | """.stripMargin)
+    assertSameRows(
+      Seq(
+        Row("Hello", 30, "New York", "USA", 2023, 4),
+        Row("Hello", 30, "New York", "USA", 2023, 4),
+        Row("Jake", 70, "California", "USA", 2023, 4),
+        Row("Jake", 70, "California", "USA", 2023, 4),
+        Row("Jane", 20, "Quebec", "Canada", 2023, 4),
+        Row("Jane", 20, "Quebec", "Canada", 2023, 4),
+        Row("John", 25, "Ontario", "Canada", 2023, 4),
+        Row("John", 25, "Ontario", "Canada", 2023, 4)),
+      frame)
+
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+
+    val allFields1 = UnresolvedStar(None)
+    val allFields2 = UnresolvedStar(None)
+
+    val projectedTable1 = Project(Seq(allFields1), table1)
+    val projectedTable2 = Project(Seq(allFields2), table2)
+
+    val expectedPlan =
+      Union(Seq(projectedTable1, projectedTable2), byName = true, allowMissingCol = true)
+
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("Search multiple tables - with table alias") {
+    val frame = sql(s"""
+                       | source = $t1, $t2 as t | where t.country = "USA"
+                       | """.stripMargin)
+    assertSameRows(
+      Seq(
+        Row("Hello", 30, "New York", "USA", 2023, 4),
+        Row("Hello", 30, "New York", "USA", 2023, 4),
+        Row("Jake", 70, "California", "USA", 2023, 4),
+        Row("Jake", 70, "California", "USA", 2023, 4)),
+      frame)
+
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+
+    val plan1 = Filter(
+      EqualTo(UnresolvedAttribute("t.country"), Literal("USA")),
+      SubqueryAlias("t", table1))
+    val plan2 = Filter(
+      EqualTo(UnresolvedAttribute("t.country"), Literal("USA")),
+      SubqueryAlias("t", table2))
+
+    val projectedTable1 = Project(Seq(UnresolvedStar(None)), plan1)
+    val projectedTable2 = Project(Seq(UnresolvedStar(None)), plan2)
+
+    val expectedPlan =
+      Union(Seq(projectedTable1, projectedTable2), byName = true, allowMissingCol = true)
+
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
 }
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJoinITSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJoinITSuite.scala
index 00e55d50a..3127325c8 100644
--- a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJoinITSuite.scala
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLJoinITSuite.scala
@@ -5,7 +5,7 @@
 
 package org.opensearch.flint.spark.ppl
 
-import org.apache.spark.sql.{QueryTest, Row}
+import org.apache.spark.sql.{AnalysisException, QueryTest, Row}
 import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedFunction, UnresolvedRelation, UnresolvedStar}
 import org.apache.spark.sql.catalyst.expressions.{Alias, And, Ascending, Divide, EqualTo, Floor, GreaterThan, LessThan, Literal, Multiply, Or, SortOrder}
 import org.apache.spark.sql.catalyst.plans.{Cross, Inner, LeftAnti, LeftOuter, LeftSemi, RightOuter}
@@ -924,4 +924,271 @@ class FlintSparkPPLJoinITSuite
       s
     }.size == 13)
   }
+
+  test("test multiple joins without table aliases") {
+    val frame = sql(s"""
+                       | source = $testTable1
+                       | | JOIN ON $testTable1.name = $testTable2.name $testTable2
+                       | | JOIN ON $testTable2.name = $testTable3.name $testTable3
+                       | | fields $testTable1.name, $testTable2.name, $testTable3.name
+                       | """.stripMargin)
+    assertSameRows(
+      Array(
+        Row("Jake", "Jake", "Jake"),
+        Row("Hello", "Hello", "Hello"),
+        Row("John", "John", "John"),
+        Row("David", "David", "David"),
+        Row("David", "David", "David"),
+        Row("Jane", "Jane", "Jane")),
+      frame)
+
+    val logicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      table1,
+      table2,
+      Inner,
+      Some(
+        EqualTo(
+          UnresolvedAttribute(s"$testTable1.name"),
+          UnresolvedAttribute(s"$testTable2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      table3,
+      Inner,
+      Some(
+        EqualTo(
+          UnresolvedAttribute(s"$testTable2.name"),
+          UnresolvedAttribute(s"$testTable3.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute(s"$testTable1.name"),
+        UnresolvedAttribute(s"$testTable2.name"),
+        UnresolvedAttribute(s"$testTable3.name")),
+      joinPlan2)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with part subquery aliases") {
+    val frame = sql(s"""
+                       | source = $testTable1
+                       | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+                       | | JOIN right = t3 ON t1.name = t3.name $testTable3
+                       | | fields t1.name, t2.name, t3.name
+                       | """.stripMargin)
+    assertSameRows(
+      Array(
+        Row("Jake", "Jake", "Jake"),
+        Row("Hello", "Hello", "Hello"),
+        Row("John", "John", "John"),
+        Row("David", "David", "David"),
+        Row("David", "David", "David"),
+        Row("Jane", "Jane", "Jane")),
+      frame)
+
+    val logicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute("t1.name"),
+        UnresolvedAttribute("t2.name"),
+        UnresolvedAttribute("t3.name")),
+      joinPlan2)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with self join 1") {
+    val frame = sql(s"""
+                       | source = $testTable1
+                       | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+                       | | JOIN right = t3 ON t1.name = t3.name $testTable3
+                       | | JOIN right = t4 ON t1.name = t4.name $testTable1
+                       | | fields t1.name, t2.name, t3.name, t4.name
+                       | """.stripMargin)
+    assertSameRows(
+      Array(
+        Row("Jake", "Jake", "Jake", "Jake"),
+        Row("Hello", "Hello", "Hello", "Hello"),
+        Row("John", "John", "John", "John"),
+        Row("David", "David", "David", "David"),
+        Row("David", "David", "David", "David"),
+        Row("Jane", "Jane", "Jane", "Jane")),
+      frame)
+
+    val logicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table1),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t4.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute("t1.name"),
+        UnresolvedAttribute("t2.name"),
+        UnresolvedAttribute("t3.name"),
+        UnresolvedAttribute("t4.name")),
+      joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with self join 2") {
+    val frame = sql(s"""
+                       | source = $testTable1
+                       | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+                       | | JOIN right = t3 ON t1.name = t3.name $testTable3
+                       | | JOIN ON t1.name = t4.name
+                       |   [
+                       |     source = $testTable1
+                       |   ] as t4
+                       | | fields t1.name, t2.name, t3.name, t4.name
+                       | """.stripMargin)
+    assertSameRows(
+      Array(
+        Row("Jake", "Jake", "Jake", "Jake"),
+        Row("Hello", "Hello", "Hello", "Hello"),
+        Row("John", "John", "John", "John"),
+        Row("David", "David", "David", "David"),
+        Row("David", "David", "David", "David"),
+        Row("Jane", "Jane", "Jane", "Jane")),
+      frame)
+
+    val logicalPlan = frame.queryExecution.logical
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table1),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t4.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute("t1.name"),
+        UnresolvedAttribute("t2.name"),
+        UnresolvedAttribute("t3.name"),
+        UnresolvedAttribute("t4.name")),
+      joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("check access the reference by aliases") {
+    var frame = sql(s"""
+                       | source = $testTable1
+                       | | JOIN left = t1 ON t1.name = t2.name $testTable2 as t2
+                       | | fields t1.name, t2.name
+                       | """.stripMargin)
+    assert(frame.collect().length > 0)
+
+    frame = sql(s"""
+                   | source = $testTable1 as t1
+                   | | JOIN ON t1.name = t2.name $testTable2 as t2
+                   | | fields t1.name, t2.name
+                   | """.stripMargin)
+    assert(frame.collect().length > 0)
+
+    frame = sql(s"""
+                   | source = $testTable1
+                   | | JOIN left = t1 ON t1.name = t2.name [ source = $testTable2 ] as t2
+                   | | fields t1.name, t2.name
+                   | """.stripMargin)
+    assert(frame.collect().length > 0)
+
+    frame = sql(s"""
+                   | source = $testTable1
+                   | | JOIN left = t1 ON t1.name = t2.name [ source = $testTable2 as t2 ]
+                   | | fields t1.name, t2.name
+                   | """.stripMargin)
+    assert(frame.collect().length > 0)
+  }
+
+  test("access the reference by override aliases should throw exception") {
+    var ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2 as tt
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+
+    ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1 as tt
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+
+    ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name [ source = $testTable2 as tt ]
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+
+    ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1
+         | | JOIN left = t1 ON t1.name = t2.name [ source = $testTable2 as tt ] as t2
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+
+    ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name [ source = $testTable2 ] as tt
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+
+    ex = intercept[AnalysisException](sql(s"""
+         | source = $testTable1 as tt
+         | | JOIN left = t1 ON t1.name = t2.name $testTable2 as t2
+         | | fields tt.name
+         | """.stripMargin))
+    assert(ex.getMessage.contains("`tt`.`name` cannot be resolved"))
+  }
 }
diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
index 06dffa55c..123d1e15a 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
@@ -339,7 +339,7 @@ joinType
    ;
 
 sideAlias
-   : LEFT EQUAL leftAlias = ident COMMA? RIGHT EQUAL rightAlias = ident
+   : (LEFT EQUAL leftAlias = ident)? COMMA? (RIGHT EQUAL rightAlias = ident)?
    ;
 
 joinCriteria
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/DescribeRelation.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/DescribeRelation.java
index b513d01bf..dd9947329 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/DescribeRelation.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/DescribeRelation.java
@@ -8,12 +8,14 @@
 import lombok.ToString;
 import org.opensearch.sql.ast.expression.UnresolvedExpression;
 
+import java.util.Collections;
+
 /**
  * Extend Relation to describe the table itself
  */
 @ToString
 public class DescribeRelation extends Relation{
     public DescribeRelation(UnresolvedExpression tableName) {
-        super(tableName);
+        super(Collections.singletonList(tableName));
     }
 }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Join.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Join.java
index 89f787d34..176902911 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Join.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Join.java
@@ -25,15 +25,15 @@
 public class Join extends UnresolvedPlan {
     private UnresolvedPlan left;
     private final UnresolvedPlan right;
-    private final String leftAlias;
-    private final String rightAlias;
+    private final Optional<String> leftAlias;
+    private final Optional<String> rightAlias;
     private final JoinType joinType;
     private final Optional<UnresolvedExpression> joinCondition;
     private final JoinHint joinHint;
 
     @Override
     public UnresolvedPlan attach(UnresolvedPlan child) {
-        this.left = new SubqueryAlias(leftAlias, child);
+        this.left = leftAlias.isEmpty() ? child : new SubqueryAlias(leftAlias.get(), child);
         return this;
     }
 
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Relation.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Relation.java
index 1b30a7998..d8ea104a4 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Relation.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Relation.java
@@ -6,53 +6,34 @@
 package org.opensearch.sql.ast.tree;
 
 import com.google.common.collect.ImmutableList;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
-import lombok.Setter;
 import lombok.ToString;
 import org.opensearch.sql.ast.AbstractNodeVisitor;
 import org.opensearch.sql.ast.expression.QualifiedName;
 import org.opensearch.sql.ast.expression.UnresolvedExpression;
 
-import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
 
 /** Logical plan node of Relation, the interface for building the searching sources. */
-@AllArgsConstructor
 @ToString
+@Getter
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Relation extends UnresolvedPlan {
   private static final String COMMA = ",";
 
-  private final List<UnresolvedExpression> tableName;
-
-  public Relation(UnresolvedExpression tableName) {
-    this(tableName, null);
-  }
-
-  public Relation(UnresolvedExpression tableName, String alias) {
-    this.tableName = Arrays.asList(tableName);
-    this.alias = alias;
-  }
-
-  /** Optional alias name for the relation. */
-  @Setter @Getter private String alias;
-
-  /**
-   * Return table name.
-   *
-   * @return table name
-   */
-  public List<String> getTableName() {
-    return tableName.stream().map(Object::toString).collect(Collectors.toList());
-  }
+  // A relation could contain more than one table/index names, such as
+  // source=account1, account2
+  // source=`account1`,`account2`
+  // source=`account*`
+  // They translated into union call with fields.
+  private final List<UnresolvedExpression> tableNames;
 
   public List<QualifiedName> getQualifiedNames() {
-    return tableName.stream().map(t -> (QualifiedName) t).collect(Collectors.toList());
+    return tableNames.stream().map(t -> (QualifiedName) t).collect(Collectors.toList());
   }
 
   /**
@@ -63,11 +44,11 @@ public List<QualifiedName> getQualifiedNames() {
    * @return TableQualifiedName.
    */
   public QualifiedName getTableQualifiedName() {
-    if (tableName.size() == 1) {
-      return (QualifiedName) tableName.get(0);
+    if (tableNames.size() == 1) {
+      return (QualifiedName) tableNames.get(0);
     } else {
       return new QualifiedName(
-          tableName.stream()
+          tableNames.stream()
               .map(UnresolvedExpression::toString)
               .collect(Collectors.joining(COMMA)));
     }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/SubqueryAlias.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/SubqueryAlias.java
index 29c3d4b90..ba66cca80 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/SubqueryAlias.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/SubqueryAlias.java
@@ -6,19 +6,14 @@
 package org.opensearch.sql.ast.tree;
 
 import com.google.common.collect.ImmutableList;
-import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 import org.opensearch.sql.ast.AbstractNodeVisitor;
 
 import java.util.List;
-import java.util.Objects;
 
-@AllArgsConstructor
 @EqualsAndHashCode(callSuper = false)
-@RequiredArgsConstructor
 @ToString
 public class SubqueryAlias extends UnresolvedPlan {
     @Getter private final String alias;
@@ -32,6 +27,11 @@ public SubqueryAlias(UnresolvedPlan child, String suffix) {
         this.child = child;
     }
 
+    public SubqueryAlias(String alias, UnresolvedPlan child) {
+        this.alias = alias;
+        this.child = child;
+    }
+
     public List<UnresolvedPlan> getChild() {
         return ImmutableList.of(child);
     }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystExpressionVisitor.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystExpressionVisitor.java
index a0506ceee..4c8d117b3 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystExpressionVisitor.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystExpressionVisitor.java
@@ -110,6 +110,11 @@ public Expression analyze(UnresolvedExpression unresolved, CatalystPlanContext c
         return unresolved.accept(this, context);
     }
 
+    /** This method is only for analyze the join condition expression */
+    public Expression analyzeJoinCondition(UnresolvedExpression unresolved, CatalystPlanContext context) {
+        return context.resolveJoinCondition(unresolved, this::analyze);
+    }
+
     @Override
     public Expression visitLiteral(Literal node, CatalystPlanContext context) {
         return context.getNamedParseExpressions().push(new org.apache.spark.sql.catalyst.expressions.Literal(
@@ -197,6 +202,11 @@ public Expression visitCompare(Compare node, CatalystPlanContext context) {
 
     @Override
     public Expression visitQualifiedName(QualifiedName node, CatalystPlanContext context) {
+        // When the qualified name is part of join condition, for example: table1.id = table2.id
+        // findRelation(context.traversalContext() only returns relation table1 which cause table2.id fail to resolve
+        if (context.isResolvingJoinCondition()) {
+            return context.getNamedParseExpressions().push(UnresolvedAttribute$.MODULE$.apply(seq(node.getParts())));
+        }
         List<UnresolvedRelation> relation = findRelation(context.traversalContext());
         if (!relation.isEmpty()) {
             Optional<QualifiedName> resolveField = resolveField(relation, node, context.getRelations());
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystPlanContext.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystPlanContext.java
index 61762f616..53dc17576 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystPlanContext.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystPlanContext.java
@@ -5,6 +5,7 @@
 
 package org.opensearch.sql.ppl;
 
+import lombok.Getter;
 import org.apache.spark.sql.catalyst.analysis.UnresolvedRelation;
 import org.apache.spark.sql.catalyst.expressions.AttributeReference;
 import org.apache.spark.sql.catalyst.expressions.Expression;
@@ -39,19 +40,19 @@ public class CatalystPlanContext {
     /**
      * Catalyst relations list
      **/
-    private List<UnresolvedExpression> projectedFields = new ArrayList<>();
+    @Getter private List<UnresolvedExpression> projectedFields = new ArrayList<>();
     /**
      * Catalyst relations list
      **/
-    private List<LogicalPlan> relations = new ArrayList<>();
+    @Getter private List<LogicalPlan> relations = new ArrayList<>();
     /**
      * Catalyst SubqueryAlias list
      **/
-    private List<LogicalPlan> subqueryAlias = new ArrayList<>();
+    @Getter private List<LogicalPlan> subqueryAlias = new ArrayList<>();
     /**
      * Catalyst evolving logical plan
      **/
-    private Stack<LogicalPlan> planBranches = new Stack<>();
+    @Getter private Stack<LogicalPlan> planBranches = new Stack<>();
     /**
      * The current traversal context the visitor is going threw
      */
@@ -60,28 +61,12 @@ public class CatalystPlanContext {
     /**
      * NamedExpression contextual parameters
      **/
-    private final Stack<org.apache.spark.sql.catalyst.expressions.Expression> namedParseExpressions = new Stack<>();
+    @Getter private final Stack<org.apache.spark.sql.catalyst.expressions.Expression> namedParseExpressions = new Stack<>();
 
     /**
      * Grouping NamedExpression contextual parameters
      **/
-    private final Stack<org.apache.spark.sql.catalyst.expressions.Expression> groupingParseExpressions = new Stack<>();
-
-    public Stack<LogicalPlan> getPlanBranches() {
-        return planBranches;
-    }
-
-    public List<LogicalPlan> getRelations() {
-        return relations;
-    }
-
-    public List<LogicalPlan> getSubqueryAlias() {
-        return subqueryAlias;
-    }
-
-    public List<UnresolvedExpression> getProjectedFields() {
-        return projectedFields;
-    }
+    @Getter private final Stack<org.apache.spark.sql.catalyst.expressions.Expression> groupingParseExpressions = new Stack<>();
 
     public LogicalPlan getPlan() {
         if (this.planBranches.isEmpty()) return null;
@@ -101,10 +86,6 @@ public Stack<LogicalPlan> traversalContext() {
         return planTraversalContext;
     }
 
-    public Stack<Expression> getNamedParseExpressions() {
-        return namedParseExpressions;
-    }
-
     public void setNamedParseExpressions(Stack<org.apache.spark.sql.catalyst.expressions.Expression> namedParseExpressions) {
         this.namedParseExpressions.clear();
         this.namedParseExpressions.addAll(namedParseExpressions);
@@ -114,10 +95,6 @@ public Optional<Expression> popNamedParseExpressions() {
         return namedParseExpressions.isEmpty() ? Optional.empty() : Optional.of(namedParseExpressions.pop());
     }
 
-    public Stack<Expression> getGroupingParseExpressions() {
-        return groupingParseExpressions;
-    }
-
     /**
      * define new field
      *
@@ -154,13 +131,13 @@ public LogicalPlan withProjectedFields(List<UnresolvedExpression> projectedField
         this.projectedFields.addAll(projectedFields);
         return getPlan();
     }
-    
+
     public LogicalPlan applyBranches(List<Function<LogicalPlan, LogicalPlan>> plans) {
         plans.forEach(plan -> with(plan.apply(planBranches.get(0))));
         planBranches.remove(0);
         return getPlan();
-    }    
-    
+    }
+
     /**
      * append plan with evolving plans branches
      *
@@ -288,4 +265,21 @@ public static Optional<UnresolvedRelation> findRelation(LogicalPlan plan) {
         return Optional.empty();
     }
 
+    @Getter private boolean isResolvingJoinCondition = false;
+
+    /**
+     * Resolve the join condition with the given function.
+     * A flag will be set to true ahead expression resolving, then false after resolving.
+     * @param expr
+     * @param transformFunction
+     * @return
+     */
+    public Expression resolveJoinCondition(
+            UnresolvedExpression expr,
+            BiFunction<UnresolvedExpression, CatalystPlanContext, Expression> transformFunction) {
+        isResolvingJoinCondition = true;
+        Expression result = transformFunction.apply(expr, this);
+        isResolvingJoinCondition = false;
+        return result;
+    }
 }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
index 669459fba..a43378480 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
@@ -273,7 +273,8 @@ public LogicalPlan visitJoin(Join node, CatalystPlanContext context) {
         node.getChild().get(0).accept(this, context);
         return context.apply(left -> {
             LogicalPlan right = node.getRight().accept(this, context);
-            Optional<Expression> joinCondition = node.getJoinCondition().map(c -> visitExpression(c, context));
+            Optional<Expression> joinCondition = node.getJoinCondition()
+                .map(c -> expressionAnalyzer.analyzeJoinCondition(c, context));
             context.retainAllNamedParseExpressions(p -> p);
             context.retainAllPlans(p -> p);
             return join(left, right, node.getJoinType(), joinCondition, node.getJoinHint());
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
index 4e6b1f131..36a34cd06 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
@@ -155,14 +155,25 @@ public UnresolvedPlan visitJoinCommand(OpenSearchPPLParser.JoinCommandContext ct
       joinType = Join.JoinType.CROSS;
     }
     Join.JoinHint joinHint = getJoinHint(ctx.joinHintList());
-    String leftAlias = ctx.sideAlias().leftAlias.getText();
-    String rightAlias = ctx.sideAlias().rightAlias.getText();
+    Optional<String> leftAlias = ctx.sideAlias().leftAlias != null ? Optional.of(ctx.sideAlias().leftAlias.getText()) : Optional.empty();
+    Optional<String> rightAlias = Optional.empty();
     if (ctx.tableOrSubqueryClause().alias != null) {
-      // left and right aliases are required in join syntax. Setting by 'AS' causes ambiguous
-      throw new SyntaxCheckException("'AS' is not allowed in right subquery, use right=<rightAlias> instead");
+      rightAlias = Optional.of(ctx.tableOrSubqueryClause().alias.getText());
     }
+    if (ctx.sideAlias().rightAlias != null) {
+      rightAlias = Optional.of(ctx.sideAlias().rightAlias.getText());
+    }
+
     UnresolvedPlan rightRelation = visit(ctx.tableOrSubqueryClause());
-    UnresolvedPlan right = new SubqueryAlias(rightAlias, rightRelation);
+    // Add a SubqueryAlias to the right plan when the right alias is present and no duplicated alias existing in right.
+    UnresolvedPlan right;
+    if (rightAlias.isEmpty() ||
+        (rightRelation instanceof SubqueryAlias &&
+            rightAlias.get().equals(((SubqueryAlias) rightRelation).getAlias()))) {
+      right = rightRelation;
+    } else {
+      right = new SubqueryAlias(rightAlias.get(), rightRelation);
+    }
     Optional<UnresolvedExpression> joinCondition =
         ctx.joinCriteria() == null ? Optional.empty() : Optional.of(expressionBuilder.visitJoinCriteria(ctx.joinCriteria()));
 
@@ -370,7 +381,7 @@ public UnresolvedPlan visitPatternsCommand(OpenSearchPPLParser.PatternsCommandCo
   /** Lookup command */
   @Override
   public UnresolvedPlan visitLookupCommand(OpenSearchPPLParser.LookupCommandContext ctx) {
-    Relation lookupRelation = new Relation(this.internalVisitExpression(ctx.tableSource()));
+    Relation lookupRelation = new Relation(Collections.singletonList(this.internalVisitExpression(ctx.tableSource())));
     Lookup.OutputStrategy strategy =
         ctx.APPEND() != null ? Lookup.OutputStrategy.APPEND : Lookup.OutputStrategy.REPLACE;
     java.util.Map<Alias, Field> lookupMappingList = buildLookupPair(ctx.lookupMappingList().lookupPair());
@@ -509,9 +520,8 @@ public UnresolvedPlan visitTableOrSubqueryClause(OpenSearchPPLParser.TableOrSubq
 
   @Override
   public UnresolvedPlan visitTableSourceClause(OpenSearchPPLParser.TableSourceClauseContext ctx) {
-    return ctx.alias == null
-        ? new Relation(ctx.tableSource().stream().map(this::internalVisitExpression).collect(Collectors.toList()))
-        : new Relation(ctx.tableSource().stream().map(this::internalVisitExpression).collect(Collectors.toList()), ctx.alias.getText());
+    Relation relation = new Relation(ctx.tableSource().stream().map(this::internalVisitExpression).collect(Collectors.toList()));
+    return ctx.alias != null ? new SubqueryAlias(ctx.alias.getText(), relation) : relation;
   }
 
   @Override
diff --git a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanBasicQueriesTranslatorTestSuite.scala b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanBasicQueriesTranslatorTestSuite.scala
index 2a569dbdf..50ef985d6 100644
--- a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanBasicQueriesTranslatorTestSuite.scala
+++ b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanBasicQueriesTranslatorTestSuite.scala
@@ -13,7 +13,7 @@ import org.scalatest.matchers.should.Matchers
 import org.apache.spark.SparkFunSuite
 import org.apache.spark.sql.catalyst.TableIdentifier
 import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedRelation, UnresolvedStar}
-import org.apache.spark.sql.catalyst.expressions.{Ascending, Descending, GreaterThan, Literal, NamedExpression, SortOrder}
+import org.apache.spark.sql.catalyst.expressions.{Ascending, Descending, EqualTo, GreaterThan, Literal, NamedExpression, SortOrder}
 import org.apache.spark.sql.catalyst.plans.PlanTest
 import org.apache.spark.sql.catalyst.plans.logical._
 import org.apache.spark.sql.execution.command.DescribeTableCommand
@@ -292,6 +292,44 @@ class PPLLogicalPlanBasicQueriesTranslatorTestSuite
     comparePlans(expectedPlan, logPlan, false)
   }
 
+  test("Search multiple tables - with table alias") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(
+        plan(
+          pplParser,
+          """
+            | source=table1, table2, table3 as t
+            | | where t.name = 'Molly'
+            |""".stripMargin),
+        context)
+
+    val table1 = UnresolvedRelation(Seq("table1"))
+    val table2 = UnresolvedRelation(Seq("table2"))
+    val table3 = UnresolvedRelation(Seq("table3"))
+    val star = UnresolvedStar(None)
+    val plan1 = Project(
+      Seq(star),
+      Filter(
+        EqualTo(UnresolvedAttribute("t.name"), Literal("Molly")),
+        SubqueryAlias("t", table1)))
+    val plan2 = Project(
+      Seq(star),
+      Filter(
+        EqualTo(UnresolvedAttribute("t.name"), Literal("Molly")),
+        SubqueryAlias("t", table2)))
+    val plan3 = Project(
+      Seq(star),
+      Filter(
+        EqualTo(UnresolvedAttribute("t.name"), Literal("Molly")),
+        SubqueryAlias("t", table3)))
+
+    val expectedPlan =
+      Union(Seq(plan1, plan2, plan3), byName = true, allowMissingCol = true)
+
+    comparePlans(expectedPlan, logPlan, false)
+  }
+
   test("test fields + field list") {
     val context = new CatalystPlanContext
     val logPlan = planTransformer.visit(
diff --git a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJoinTranslatorTestSuite.scala b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJoinTranslatorTestSuite.scala
index 3ceff7735..f4ed397e3 100644
--- a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJoinTranslatorTestSuite.scala
+++ b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanJoinTranslatorTestSuite.scala
@@ -271,9 +271,9 @@ class PPLLogicalPlanJoinTranslatorTestSuite
       pplParser,
       s"""
          | source = $testTable1
-         | | inner JOIN left = l,right = r ON l.id = r.id $testTable2
-         | | left JOIN left = l,right = r ON l.name = r.name $testTable3
-         | | cross JOIN left = l,right = r $testTable4
+         | | inner JOIN left = l right = r ON l.id = r.id $testTable2
+         | | left JOIN left = l right = r ON l.name = r.name $testTable3
+         | | cross JOIN left = l right = r $testTable4
          | """.stripMargin)
     val logicalPlan = planTransformer.visit(logPlan, context)
     val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
@@ -443,17 +443,17 @@ class PPLLogicalPlanJoinTranslatorTestSuite
       s"""
          | source = $testTable1
          | | head 10
-         | | inner JOIN left = l,right = r ON l.id = r.id
+         | | inner JOIN left = l right = r ON l.id = r.id
          |   [
          |     source = $testTable2
          |     | where id > 10
          |   ]
-         | | left JOIN left = l,right = r ON l.name = r.name
+         | | left JOIN left = l right = r ON l.name = r.name
          |   [
          |     source = $testTable3
          |     | fields id
          |   ]
-         | | cross JOIN left = l,right = r
+         | | cross JOIN left = l right = r
          |   [
          |     source = $testTable4
          |     | sort id
@@ -565,4 +565,284 @@ class PPLLogicalPlanJoinTranslatorTestSuite
     val expectedPlan = Project(Seq(UnresolvedStar(None)), sort)
     comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
   }
+
+  test("test multiple joins with table alias") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = table1 as t1
+         | | JOIN ON t1.id = t2.id
+         |   [
+         |     source = table2 as t2
+         |   ]
+         | | JOIN ON t2.id = t3.id
+         |   [
+         |     source = table3 as t3
+         |   ]
+         | | JOIN ON t3.id = t4.id
+         |   [
+         |     source = table4 as t4
+         |   ]
+         | """.stripMargin)
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("table1"))
+    val table2 = UnresolvedRelation(Seq("table2"))
+    val table3 = UnresolvedRelation(Seq("table3"))
+    val table4 = UnresolvedRelation(Seq("table4"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.id"), UnresolvedAttribute("t2.id"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t2.id"), UnresolvedAttribute("t3.id"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table4),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t3.id"), UnresolvedAttribute("t4.id"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with table and subquery alias") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = table1 as t1
+         | | JOIN left = l right = r ON t1.id = t2.id
+         |   [
+         |     source = table2 as t2
+         |   ]
+         | | JOIN left = l right = r ON t2.id = t3.id
+         |   [
+         |     source = table3 as t3
+         |   ]
+         | | JOIN left = l right = r ON t3.id = t4.id
+         |   [
+         |     source = table4 as t4
+         |   ]
+         | """.stripMargin)
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("table1"))
+    val table2 = UnresolvedRelation(Seq("table2"))
+    val table3 = UnresolvedRelation(Seq("table3"))
+    val table4 = UnresolvedRelation(Seq("table4"))
+    val joinPlan1 = Join(
+      SubqueryAlias("l", SubqueryAlias("t1", table1)),
+      SubqueryAlias("r", SubqueryAlias("t2", table2)),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.id"), UnresolvedAttribute("t2.id"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      SubqueryAlias("l", joinPlan1),
+      SubqueryAlias("r", SubqueryAlias("t3", table3)),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t2.id"), UnresolvedAttribute("t3.id"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      SubqueryAlias("l", joinPlan2),
+      SubqueryAlias("r", SubqueryAlias("t4", table4)),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t3.id"), UnresolvedAttribute("t4.id"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins without table aliases") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = table1
+         | | JOIN ON table1.id = table2.id table2
+         | | JOIN ON table1.id = table3.id table3
+         | | JOIN ON table2.id = table4.id table4
+         | """.stripMargin)
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("table1"))
+    val table2 = UnresolvedRelation(Seq("table2"))
+    val table3 = UnresolvedRelation(Seq("table3"))
+    val table4 = UnresolvedRelation(Seq("table4"))
+    val joinPlan1 = Join(
+      table1,
+      table2,
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("table1.id"), UnresolvedAttribute("table2.id"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      table3,
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("table1.id"), UnresolvedAttribute("table3.id"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      table4,
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("table2.id"), UnresolvedAttribute("table4.id"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with part subquery aliases") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = table1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name table2
+         | | JOIN right = t3 ON t1.name = t3.name table3
+         | | JOIN right = t4 ON t2.name = t4.name table4
+         | """.stripMargin)
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("table1"))
+    val table2 = UnresolvedRelation(Seq("table2"))
+    val table3 = UnresolvedRelation(Seq("table3"))
+    val table4 = UnresolvedRelation(Seq("table4"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table4),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t2.name"), UnresolvedAttribute("t4.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with self join 1") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+         | | JOIN right = t3 ON t1.name = t3.name $testTable3
+         | | JOIN right = t4 ON t1.name = t4.name $testTable1
+         | | fields t1.name, t2.name, t3.name, t4.name
+         | """.stripMargin)
+
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table1),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t4.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute("t1.name"),
+        UnresolvedAttribute("t2.name"),
+        UnresolvedAttribute("t3.name"),
+        UnresolvedAttribute("t4.name")),
+      joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test multiple joins with self join 2") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name $testTable2
+         | | JOIN right = t3 ON t1.name = t3.name $testTable3
+         | | JOIN ON t1.name = t4.name
+         |   [
+         |     source = $testTable1
+         |   ] as t4
+         | | fields t1.name, t2.name, t3.name, t4.name
+         | """.stripMargin)
+
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val table3 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test3"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", table2),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val joinPlan2 = Join(
+      joinPlan1,
+      SubqueryAlias("t3", table3),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t3.name"))),
+      JoinHint.NONE)
+    val joinPlan3 = Join(
+      joinPlan2,
+      SubqueryAlias("t4", table1),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t4.name"))),
+      JoinHint.NONE)
+    val expectedPlan = Project(
+      Seq(
+        UnresolvedAttribute("t1.name"),
+        UnresolvedAttribute("t2.name"),
+        UnresolvedAttribute("t3.name"),
+        UnresolvedAttribute("t4.name")),
+      joinPlan3)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("test side alias will override the subquery alias") {
+    val context = new CatalystPlanContext
+    val logPlan = plan(
+      pplParser,
+      s"""
+         | source = $testTable1
+         | | JOIN left = t1 right = t2 ON t1.name = t2.name [ source = $testTable2 as ttt ] as tt
+         | | fields t1.name, t2.name
+         | """.stripMargin)
+    val logicalPlan = planTransformer.visit(logPlan, context)
+    val table1 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test1"))
+    val table2 = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_test2"))
+    val joinPlan1 = Join(
+      SubqueryAlias("t1", table1),
+      SubqueryAlias("t2", SubqueryAlias("tt", SubqueryAlias("ttt", table2))),
+      Inner,
+      Some(EqualTo(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name"))),
+      JoinHint.NONE)
+    val expectedPlan =
+      Project(Seq(UnresolvedAttribute("t1.name"), UnresolvedAttribute("t2.name")), joinPlan1)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
 }

From 48be5cc1224ea39a38dc55ba465577d24dc99d7f Mon Sep 17 00:00:00 2001
From: Lantao Jin <ltjin@amazon.com>
Date: Thu, 7 Nov 2024 10:15:04 +0800
Subject: [PATCH 3/4] Add TPC-H PPL query suite (#830)

* Add TPC-H PPL query suite

Signed-off-by: Lantao Jin <ltjin@amazon.com>

* fix failure of loading resources

Signed-off-by: Lantao Jin <ltjin@amazon.com>

* fix data_add()

Signed-off-by: Lantao Jin <ltjin@amazon.com>

* enable q21 and add docs

Signed-off-by: Lantao Jin <ltjin@amazon.com>

---------

Signed-off-by: Lantao Jin <ltjin@amazon.com>
---
 build.sbt                                     |   3 +-
 docs/ppl-lang/README.md                       |   4 +
 docs/ppl-lang/ppl-tpch.md                     | 102 ++++++++++
 .../src/integration/resources/tpch/q1.ppl     |  35 ++++
 .../src/integration/resources/tpch/q10.ppl    |  45 +++++
 .../src/integration/resources/tpch/q11.ppl    |  45 +++++
 .../src/integration/resources/tpch/q12.ppl    |  42 +++++
 .../src/integration/resources/tpch/q13.ppl    |  31 +++
 .../src/integration/resources/tpch/q14.ppl    |  25 +++
 .../src/integration/resources/tpch/q15.ppl    |  52 +++++
 .../src/integration/resources/tpch/q16.ppl    |  45 +++++
 .../src/integration/resources/tpch/q17.ppl    |  34 ++++
 .../src/integration/resources/tpch/q18.ppl    |  48 +++++
 .../src/integration/resources/tpch/q19.ppl    |  61 ++++++
 .../src/integration/resources/tpch/q2.ppl     |  62 ++++++
 .../src/integration/resources/tpch/q20.ppl    |  62 ++++++
 .../src/integration/resources/tpch/q21.ppl    |  64 +++++++
 .../src/integration/resources/tpch/q22.ppl    |  58 ++++++
 .../src/integration/resources/tpch/q3.ppl     |  33 ++++
 .../src/integration/resources/tpch/q4.ppl     |  33 ++++
 .../src/integration/resources/tpch/q5.ppl     |  36 ++++
 .../src/integration/resources/tpch/q6.ppl     |  18 ++
 .../src/integration/resources/tpch/q7.ppl     |  56 ++++++
 .../src/integration/resources/tpch/q8.ppl     |  60 ++++++
 .../src/integration/resources/tpch/q9.ppl     |  50 +++++
 .../flint/spark/ppl/tpch/TPCHQueryBase.scala  | 177 ++++++++++++++++++
 .../spark/ppl/tpch/TPCHQueryITSuite.scala     |  43 +++++
 27 files changed, 1323 insertions(+), 1 deletion(-)
 create mode 100644 docs/ppl-lang/ppl-tpch.md
 create mode 100644 integ-test/src/integration/resources/tpch/q1.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q10.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q11.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q12.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q13.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q14.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q15.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q16.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q17.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q18.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q19.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q2.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q20.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q21.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q22.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q3.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q4.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q5.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q6.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q7.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q8.ppl
 create mode 100644 integ-test/src/integration/resources/tpch/q9.ppl
 create mode 100644 integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryBase.scala
 create mode 100644 integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryITSuite.scala

diff --git a/build.sbt b/build.sbt
index 66b06d6be..1300f68a0 100644
--- a/build.sbt
+++ b/build.sbt
@@ -238,7 +238,8 @@ lazy val integtest = (project in file("integ-test"))
     inConfig(IntegrationTest)(Defaults.testSettings ++ Seq(
       IntegrationTest / javaSource := baseDirectory.value / "src/integration/java",
       IntegrationTest / scalaSource := baseDirectory.value / "src/integration/scala",
-      IntegrationTest / parallelExecution := false,
+      IntegrationTest / resourceDirectory := baseDirectory.value / "src/integration/resources",
+        IntegrationTest / parallelExecution := false,
       IntegrationTest / fork := true,
     )),
     inConfig(AwsIntegrationTest)(Defaults.testSettings ++ Seq(
diff --git a/docs/ppl-lang/README.md b/docs/ppl-lang/README.md
index d78f4c030..ef186e5f2 100644
--- a/docs/ppl-lang/README.md
+++ b/docs/ppl-lang/README.md
@@ -104,6 +104,10 @@ For additional examples see the next [documentation](PPL-Example-Commands.md).
 ### Example PPL Queries
 See samples of [PPL queries](PPL-Example-Commands.md) 
 
+---
+### TPC-H PPL Query Rewriting
+See samples of [TPC-H PPL query rewriting](ppl-tpch.md)
+
 ---
 ### Planned PPL Commands
 
diff --git a/docs/ppl-lang/ppl-tpch.md b/docs/ppl-lang/ppl-tpch.md
new file mode 100644
index 000000000..ef5846ce0
--- /dev/null
+++ b/docs/ppl-lang/ppl-tpch.md
@@ -0,0 +1,102 @@
+## TPC-H Benchmark
+
+TPC-H is a decision support benchmark designed to evaluate the performance of database systems in handling complex business-oriented queries and concurrent data modifications. The benchmark utilizes a dataset that is broadly representative of various industries, making it widely applicable. TPC-H simulates a decision support environment where large volumes of data are analyzed, intricate queries are executed, and critical business questions are answered.
+
+### Test PPL Queries
+
+TPC-H 22 test query statements: [TPCH-Query-PPL](https://github.com/opensearch-project/opensearch-spark/blob/main/integ-test/src/integration/resources/tpch)
+
+### Data Preparation
+
+#### Option 1 - from PyPi
+
+```
+# Create the virtual environment
+python3 -m venv .venv
+
+# Activate the virtual environment
+. .venv/bin/activate
+
+pip install tpch-datagen
+```
+
+#### Option 2 - from source
+
+```
+git clone https://github.com/gizmodata/tpch-datagen
+
+cd tpch-datagen
+
+# Create the virtual environment
+python3 -m venv .venv
+
+# Activate the virtual environment
+. .venv/bin/activate
+
+# Upgrade pip, setuptools, and wheel
+pip install --upgrade pip setuptools wheel
+
+# Install TPC-H Datagen - in editable mode with client and dev dependencies
+pip install --editable .[dev]
+```
+
+#### Usage
+
+Here are the options for the tpch-datagen command:
+```
+tpch-datagen --help
+Usage: tpch-datagen [OPTIONS]
+
+Options:
+  --version / --no-version        Prints the TPC-H Datagen package version and
+                                  exits.  [required]
+  --scale-factor INTEGER          The TPC-H Scale Factor to use for data
+                                  generation.
+  --data-directory TEXT           The target output data directory to put the
+                                  files into  [default: data; required]
+  --work-directory TEXT           The work directory to use for data
+                                  generation.  [default: /tmp; required]
+  --overwrite / --no-overwrite    Can we overwrite the target directory if it
+                                  already exists...  [default: no-overwrite;
+                                  required]
+  --num-chunks INTEGER            The number of chunks that will be generated
+                                  - more chunks equals smaller memory
+                                  requirements, but more files generated.
+                                  [default: 10; required]
+  --num-processes INTEGER         The maximum number of processes for the
+                                  multi-processing pool to use for data
+                                  generation.  [default: 10; required]
+  --duckdb-threads INTEGER        The number of DuckDB threads to use for data
+                                  generation (within each job process).
+                                  [default: 1; required]
+  --per-thread-output / --no-per-thread-output
+                                  Controls whether to write the output to a
+                                  single file or multiple files (for each
+                                  process).  [default: per-thread-output;
+                                  required]
+  --compression-method [none|snappy|gzip|zstd]
+                                  The compression method to use for the
+                                  parquet files generated.  [default: zstd;
+                                  required]
+  --file-size-bytes TEXT          The target file size for the parquet files
+                                  generated.  [default: 100m; required]
+  --help                          Show this message and exit.
+```
+
+### Generate 1 GB data with zstd (by default) compression
+
+```
+tpch-datagen --scale-factor 1
+```
+
+### Generate 10 GB data with snappy compression
+
+```
+tpch-datagen --scale-factor 10 --compression-method snappy
+```
+
+### Query Test
+
+All TPC-H PPL Queries located in `integ-test/src/integration/resources/tpch` folder.
+
+To test all queries, run `org.opensearch.flint.spark.ppl.tpch.TPCHQueryITSuite`.
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q1.ppl b/integ-test/src/integration/resources/tpch/q1.ppl
new file mode 100644
index 000000000..885ce35c6
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q1.ppl
@@ -0,0 +1,35 @@
+/*
+select
+    l_returnflag,
+    l_linestatus,
+    sum(l_quantity) as sum_qty,
+    sum(l_extendedprice) as sum_base_price,
+    sum(l_extendedprice * (1 - l_discount)) as sum_disc_price,
+    sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) as sum_charge,
+    avg(l_quantity) as avg_qty,
+    avg(l_extendedprice) as avg_price,
+    avg(l_discount) as avg_disc,
+    count(*) as count_order
+from
+    lineitem
+where
+    l_shipdate <= date '1998-12-01' - interval '90' day
+group by
+    l_returnflag,
+    l_linestatus
+order by
+    l_returnflag,
+    l_linestatus
+*/
+
+source = lineitem
+| where l_shipdate <= subdate(date('1998-12-01'), 90)
+| stats sum(l_quantity) as sum_qty,
+        sum(l_extendedprice) as sum_base_price,
+        sum(l_extendedprice * (1 - l_discount)) as sum_disc_price,
+        sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) as sum_charge,
+        avg(l_quantity) as avg_qty, avg(l_extendedprice) as avg_price,
+        avg(l_discount) as avg_disc,
+        count() as count_order
+  by l_returnflag, l_linestatus
+| sort l_returnflag, l_linestatus
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q10.ppl b/integ-test/src/integration/resources/tpch/q10.ppl
new file mode 100644
index 000000000..10a050785
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q10.ppl
@@ -0,0 +1,45 @@
+/*
+select
+    c_custkey,
+    c_name,
+    sum(l_extendedprice * (1 - l_discount)) as revenue,
+    c_acctbal,
+    n_name,
+    c_address,
+    c_phone,
+    c_comment
+from
+    customer,
+    orders,
+    lineitem,
+    nation
+where
+    c_custkey = o_custkey
+    and l_orderkey = o_orderkey
+    and o_orderdate >= date '1993-10-01'
+    and o_orderdate < date '1993-10-01' + interval '3' month
+    and l_returnflag = 'R'
+    and c_nationkey = n_nationkey
+group by
+    c_custkey,
+    c_name,
+    c_acctbal,
+    c_phone,
+    n_name,
+    c_address,
+    c_comment
+order by
+    revenue desc
+limit 20
+*/
+
+source = customer
+| join ON c_custkey = o_custkey orders
+| join ON l_orderkey = o_orderkey lineitem
+| join ON c_nationkey = n_nationkey nation
+| where o_orderdate >= date('1993-10-01')
+  AND o_orderdate < date_add(date('1993-10-01'), interval 3 month)
+  AND l_returnflag = 'R'
+| stats sum(l_extendedprice * (1 - l_discount)) as revenue by c_custkey, c_name, c_acctbal, c_phone, n_name, c_address, c_comment
+| sort - revenue
+| head 20
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q11.ppl b/integ-test/src/integration/resources/tpch/q11.ppl
new file mode 100644
index 000000000..3a55d986e
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q11.ppl
@@ -0,0 +1,45 @@
+/*
+select
+    ps_partkey,
+    sum(ps_supplycost * ps_availqty) as value
+from
+    partsupp,
+    supplier,
+    nation
+where
+    ps_suppkey = s_suppkey
+    and s_nationkey = n_nationkey
+    and n_name = 'GERMANY'
+group by
+    ps_partkey having
+        sum(ps_supplycost * ps_availqty) > (
+            select
+                sum(ps_supplycost * ps_availqty) * 0.0001000000
+            from
+                partsupp,
+                supplier,
+                nation
+            where
+                ps_suppkey = s_suppkey
+                and s_nationkey = n_nationkey
+                and n_name = 'GERMANY'
+        )
+order by
+    value desc
+*/
+
+source = partsupp
+| join ON ps_suppkey = s_suppkey supplier
+| join ON s_nationkey = n_nationkey nation
+| where n_name = 'GERMANY'
+| stats sum(ps_supplycost * ps_availqty) as value by ps_partkey
+| where value > [
+    source = partsupp
+    | join ON ps_suppkey = s_suppkey supplier
+    | join ON s_nationkey = n_nationkey nation
+    | where n_name = 'GERMANY'
+    | stats sum(ps_supplycost * ps_availqty) as check
+    | eval threshold = check * 0.0001000000
+    | fields threshold
+  ]
+| sort - value
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q12.ppl b/integ-test/src/integration/resources/tpch/q12.ppl
new file mode 100644
index 000000000..79672d844
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q12.ppl
@@ -0,0 +1,42 @@
+/*
+select
+    l_shipmode,
+    sum(case
+        when o_orderpriority = '1-URGENT'
+            or o_orderpriority = '2-HIGH'
+            then 1
+        else 0
+    end) as high_line_count,
+    sum(case
+        when o_orderpriority <> '1-URGENT'
+            and o_orderpriority <> '2-HIGH'
+            then 1
+        else 0
+    end) as low_line_count
+from
+    orders,
+    lineitem
+where
+    o_orderkey = l_orderkey
+    and l_shipmode in ('MAIL', 'SHIP')
+    and l_commitdate < l_receiptdate
+    and l_shipdate < l_commitdate
+    and l_receiptdate >= date '1994-01-01'
+    and l_receiptdate < date '1994-01-01' + interval '1' year
+group by
+    l_shipmode
+order by
+    l_shipmode
+*/
+
+source = orders
+| join ON o_orderkey = l_orderkey lineitem
+| where l_commitdate < l_receiptdate
+    and l_shipdate < l_commitdate
+    and l_shipmode in ('MAIL', 'SHIP')
+    and l_receiptdate >= date('1994-01-01')
+    and l_receiptdate < date_add(date('1994-01-01'), interval 1 year)
+| stats sum(case(o_orderpriority = '1-URGENT' or o_orderpriority = '2-HIGH', 1 else 0)) as high_line_count,
+        sum(case(o_orderpriority != '1-URGENT' and o_orderpriority != '2-HIGH', 1 else 0)) as low_line_countby
+        by l_shipmode
+| sort l_shipmode
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q13.ppl b/integ-test/src/integration/resources/tpch/q13.ppl
new file mode 100644
index 000000000..6e77c9b0a
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q13.ppl
@@ -0,0 +1,31 @@
+/*
+select
+    c_count,
+    count(*) as custdist
+from
+    (
+        select
+            c_custkey,
+            count(o_orderkey) as c_count
+        from
+            customer left outer join orders on
+                c_custkey = o_custkey
+                and o_comment not like '%special%requests%'
+        group by
+            c_custkey
+    ) as c_orders
+group by
+    c_count
+order by
+    custdist desc,
+    c_count desc
+*/
+
+source = [
+    source = customer
+    | left outer join ON c_custkey = o_custkey AND not like(o_comment, '%special%requests%')
+      orders
+    | stats count(o_orderkey) as c_count by c_custkey
+  ] as c_orders
+| stats count() as custdist by c_count
+| sort - custdist, - c_count
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q14.ppl b/integ-test/src/integration/resources/tpch/q14.ppl
new file mode 100644
index 000000000..553f1e549
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q14.ppl
@@ -0,0 +1,25 @@
+/*
+select
+    100.00 * sum(case
+        when p_type like 'PROMO%'
+            then l_extendedprice * (1 - l_discount)
+        else 0
+    end) / sum(l_extendedprice * (1 - l_discount)) as promo_revenue
+from
+    lineitem,
+    part
+where
+    l_partkey = p_partkey
+    and l_shipdate >= date '1995-09-01'
+    and l_shipdate < date '1995-09-01' + interval '1' month
+*/
+
+source = lineitem
+| join ON l_partkey = p_partkey
+    AND l_shipdate >= date('1995-09-01')
+    AND l_shipdate < date_add(date('1995-09-01'), interval 1 month)
+  part
+| stats sum(case(like(p_type, 'PROMO%'), l_extendedprice * (1 - l_discount) else 0)) as sum1,
+        sum(l_extendedprice * (1 - l_discount)) as sum2
+| eval promo_revenue = 100.00 * sum1 / sum2 // Stats and Eval commands can combine when issues/819 resolved
+| fields promo_revenue
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q15.ppl b/integ-test/src/integration/resources/tpch/q15.ppl
new file mode 100644
index 000000000..96f5ecea2
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q15.ppl
@@ -0,0 +1,52 @@
+/*
+with revenue0 as
+    (select
+        l_suppkey as supplier_no,
+        sum(l_extendedprice * (1 - l_discount)) as total_revenue
+    from
+        lineitem
+    where
+        l_shipdate >= date '1996-01-01'
+        and l_shipdate < date '1996-01-01' + interval '3' month
+    group by
+        l_suppkey)
+select
+    s_suppkey,
+    s_name,
+    s_address,
+    s_phone,
+    total_revenue
+from
+    supplier,
+    revenue0
+where
+    s_suppkey = supplier_no
+    and total_revenue = (
+        select
+            max(total_revenue)
+        from
+            revenue0
+    )
+order by
+    s_suppkey
+*/
+
+// CTE is unsupported in PPL
+source = supplier
+| join right = revenue0 ON s_suppkey = supplier_no [
+    source = lineitem
+    | where l_shipdate >= date('1996-01-01') AND l_shipdate < date_add(date('1996-01-01'), interval 3 month)
+    | eval supplier_no = l_suppkey
+    | stats sum(l_extendedprice * (1 - l_discount)) as total_revenue by supplier_no
+  ]
+| where total_revenue = [
+    source = [
+        source = lineitem
+        | where l_shipdate >= date('1996-01-01') AND l_shipdate < date_add(date('1996-01-01'), interval 3 month)
+        | eval supplier_no = l_suppkey
+        | stats sum(l_extendedprice * (1 - l_discount)) as total_revenue by supplier_no
+      ]
+    | stats max(total_revenue)
+  ]
+| sort s_suppkey
+| fields s_suppkey, s_name, s_address, s_phone, total_revenue
diff --git a/integ-test/src/integration/resources/tpch/q16.ppl b/integ-test/src/integration/resources/tpch/q16.ppl
new file mode 100644
index 000000000..4c5765f04
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q16.ppl
@@ -0,0 +1,45 @@
+/*
+select
+    p_brand,
+    p_type,
+    p_size,
+    count(distinct ps_suppkey) as supplier_cnt
+from
+    partsupp,
+    part
+where
+    p_partkey = ps_partkey
+    and p_brand <> 'Brand#45'
+    and p_type not like 'MEDIUM POLISHED%'
+    and p_size in (49, 14, 23, 45, 19, 3, 36, 9)
+    and ps_suppkey not in (
+        select
+            s_suppkey
+        from
+            supplier
+        where
+            s_comment like '%Customer%Complaints%'
+    )
+group by
+    p_brand,
+    p_type,
+    p_size
+order by
+    supplier_cnt desc,
+    p_brand,
+    p_type,
+    p_size
+*/
+
+source = partsupp
+| join ON p_partkey = ps_partkey part
+| where p_brand != 'Brand#45'
+    and not like(p_type, 'MEDIUM POLISHED%')
+    and p_size in (49, 14, 23, 45, 19, 3, 36, 9)
+    and ps_suppkey not in [
+          source = supplier
+          | where like(s_comment, '%Customer%Complaints%')
+          | fields s_suppkey
+        ]
+| stats distinct_count(ps_suppkey) as supplier_cnt by p_brand, p_type, p_size
+| sort - supplier_cnt, p_brand, p_type, p_size
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q17.ppl b/integ-test/src/integration/resources/tpch/q17.ppl
new file mode 100644
index 000000000..994b7ee18
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q17.ppl
@@ -0,0 +1,34 @@
+/*
+select
+    sum(l_extendedprice) / 7.0 as avg_yearly
+from
+    lineitem,
+    part
+where
+    p_partkey = l_partkey
+    and p_brand = 'Brand#23'
+    and p_container = 'MED BOX'
+    and l_quantity < (
+        select
+            0.2 * avg(l_quantity)
+        from
+            lineitem
+        where
+            l_partkey = p_partkey
+    )
+*/
+
+source = lineitem
+| join ON p_partkey = l_partkey part
+| where p_brand = 'Brand#23'
+    and p_container = 'MED BOX'
+    and l_quantity < [
+          source = lineitem
+          | where l_partkey = p_partkey
+          | stats avg(l_quantity) as avg
+          | eval `0.2 * avg` = 0.2 * avg // Stats and Eval commands can combine when issues/819 resolved
+          | fields `0.2 * avg`
+        ]
+| stats sum(l_extendedprice) as sum
+| eval avg_yearly = sum / 7.0 // Stats and Eval commands can combine when issues/819 resolved
+| fields avg_yearly
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q18.ppl b/integ-test/src/integration/resources/tpch/q18.ppl
new file mode 100644
index 000000000..1dab3d473
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q18.ppl
@@ -0,0 +1,48 @@
+/*
+select
+    c_name,
+    c_custkey,
+    o_orderkey,
+    o_orderdate,
+    o_totalprice,
+    sum(l_quantity)
+from
+    customer,
+    orders,
+    lineitem
+where
+    o_orderkey in (
+        select
+            l_orderkey
+        from
+            lineitem
+        group by
+            l_orderkey having
+                sum(l_quantity) > 300
+    )
+    and c_custkey = o_custkey
+    and o_orderkey = l_orderkey
+group by
+    c_name,
+    c_custkey,
+    o_orderkey,
+    o_orderdate,
+    o_totalprice
+order by
+    o_totalprice desc,
+    o_orderdate
+limit 100
+*/
+
+source = customer
+| join ON c_custkey = o_custkey orders
+| join ON o_orderkey = l_orderkey lineitem
+| where o_orderkey in [
+    source = lineitem
+    | stats sum(l_quantity) as sum by l_orderkey
+    | where sum > 300
+    | fields l_orderkey
+  ]
+| stats sum(l_quantity) by c_name, c_custkey, o_orderkey, o_orderdate, o_totalprice
+| sort - o_totalprice, o_orderdate
+| head 100
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q19.ppl b/integ-test/src/integration/resources/tpch/q19.ppl
new file mode 100644
index 000000000..630d63bcc
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q19.ppl
@@ -0,0 +1,61 @@
+/*
+select
+    sum(l_extendedprice* (1 - l_discount)) as revenue
+from
+    lineitem,
+    part
+where
+    (
+        p_partkey = l_partkey
+        and p_brand = 'Brand#12'
+        and p_container in ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
+        and l_quantity >= 1 and l_quantity <= 1 + 10
+        and p_size between 1 and 5
+        and l_shipmode in ('AIR', 'AIR REG')
+        and l_shipinstruct = 'DELIVER IN PERSON'
+    )
+    or
+    (
+        p_partkey = l_partkey
+        and p_brand = 'Brand#23'
+        and p_container in ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
+        and l_quantity >= 10 and l_quantity <= 10 + 10
+        and p_size between 1 and 10
+        and l_shipmode in ('AIR', 'AIR REG')
+        and l_shipinstruct = 'DELIVER IN PERSON'
+    )
+    or
+    (
+        p_partkey = l_partkey
+        and p_brand = 'Brand#34'
+        and p_container in ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
+        and l_quantity >= 20 and l_quantity <= 20 + 10
+        and p_size between 1 and 15
+        and l_shipmode in ('AIR', 'AIR REG')
+        and l_shipinstruct = 'DELIVER IN PERSON'
+    )
+*/
+
+source = lineitem
+| join ON p_partkey = l_partkey
+     and p_brand = 'Brand#12'
+     and p_container in ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
+     and l_quantity >= 1 and l_quantity <= 1 + 10
+     and p_size between 1 and 5
+     and l_shipmode in ('AIR', 'AIR REG')
+     and l_shipinstruct = 'DELIVER IN PERSON'
+     OR p_partkey = l_partkey
+     and p_brand = 'Brand#23'
+     and p_container in ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
+     and l_quantity >= 10 and l_quantity <= 10 + 10
+     and p_size between 1 and 10
+     and l_shipmode in ('AIR', 'AIR REG')
+     and l_shipinstruct = 'DELIVER IN PERSON'
+     OR p_partkey = l_partkey
+     and p_brand = 'Brand#34'
+     and p_container in ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
+     and l_quantity >= 20 and l_quantity <= 20 + 10
+     and p_size between 1 and 15
+     and l_shipmode in ('AIR', 'AIR REG')
+     and l_shipinstruct = 'DELIVER IN PERSON'
+  part
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q2.ppl b/integ-test/src/integration/resources/tpch/q2.ppl
new file mode 100644
index 000000000..aa95d9d14
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q2.ppl
@@ -0,0 +1,62 @@
+/*
+select
+    s_acctbal,
+    s_name,
+    n_name,
+    p_partkey,
+    p_mfgr,
+    s_address,
+    s_phone,
+    s_comment
+from
+    part,
+    supplier,
+    partsupp,
+    nation,
+    region
+where
+    p_partkey = ps_partkey
+    and s_suppkey = ps_suppkey
+    and p_size = 15
+    and p_type like '%BRASS'
+    and s_nationkey = n_nationkey
+    and n_regionkey = r_regionkey
+    and r_name = 'EUROPE'
+    and ps_supplycost = (
+        select
+            min(ps_supplycost)
+        from
+            partsupp,
+            supplier,
+            nation,
+            region
+        where
+            p_partkey = ps_partkey
+            and s_suppkey = ps_suppkey
+            and s_nationkey = n_nationkey
+            and n_regionkey = r_regionkey
+            and r_name = 'EUROPE'
+    )
+order by
+    s_acctbal desc,
+    n_name,
+    s_name,
+    p_partkey
+limit 100
+*/
+
+source = part
+| join ON p_partkey = ps_partkey partsupp
+| join ON s_suppkey = ps_suppkey supplier
+| join ON s_nationkey = n_nationkey nation
+| join ON n_regionkey = r_regionkey region
+| where p_size = 15 AND like(p_type, '%BRASS') AND r_name = 'EUROPE' AND ps_supplycost = [
+    source = partsupp
+    | join ON s_suppkey = ps_suppkey supplier
+    | join ON s_nationkey = n_nationkey nation
+    | join ON n_regionkey = r_regionkey region
+    | where r_name = 'EUROPE'
+    | stats MIN(ps_supplycost)
+  ]
+| sort - s_acctbal, n_name, s_name, p_partkey
+| head 100
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q20.ppl b/integ-test/src/integration/resources/tpch/q20.ppl
new file mode 100644
index 000000000..08bd21277
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q20.ppl
@@ -0,0 +1,62 @@
+/*
+select
+    s_name,
+    s_address
+from
+    supplier,
+    nation
+where
+    s_suppkey in (
+        select
+            ps_suppkey
+        from
+            partsupp
+        where
+            ps_partkey in (
+                select
+                    p_partkey
+                from
+                    part
+                where
+                    p_name like 'forest%'
+            )
+            and ps_availqty > (
+                select
+                    0.5 * sum(l_quantity)
+                from
+                    lineitem
+                where
+                    l_partkey = ps_partkey
+                    and l_suppkey = ps_suppkey
+                    and l_shipdate >= date '1994-01-01'
+                    and l_shipdate < date '1994-01-01' + interval '1' year
+            )
+    )
+    and s_nationkey = n_nationkey
+    and n_name = 'CANADA'
+order by
+    s_name
+*/
+
+source = supplier
+| join ON s_nationkey = n_nationkey nation
+| where n_name = 'CANADA'
+  and s_suppkey in [
+    source = partsupp
+    | where ps_partkey in [
+        source = part
+        | where like(p_name, 'forest%')
+        | fields p_partkey
+      ]
+      and ps_availqty > [
+        source = lineitem
+        | where l_partkey = ps_partkey
+          and l_suppkey = ps_suppkey
+          and l_shipdate >= date('1994-01-01')
+          and l_shipdate < date_add(date('1994-01-01'), interval 1 year)
+        | stats sum(l_quantity) as sum_l_quantity
+        | eval half_sum_l_quantity = 0.5 * sum_l_quantity // Stats and Eval commands can combine when issues/819 resolved
+        | fields half_sum_l_quantity
+      ]
+    | fields ps_suppkey
+  ]
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q21.ppl b/integ-test/src/integration/resources/tpch/q21.ppl
new file mode 100644
index 000000000..0eb7149f6
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q21.ppl
@@ -0,0 +1,64 @@
+/*
+select
+    s_name,
+    count(*) as numwait
+from
+    supplier,
+    lineitem l1,
+    orders,
+    nation
+where
+    s_suppkey = l1.l_suppkey
+    and o_orderkey = l1.l_orderkey
+    and o_orderstatus = 'F'
+    and l1.l_receiptdate > l1.l_commitdate
+    and exists (
+        select
+            *
+        from
+            lineitem l2
+        where
+            l2.l_orderkey = l1.l_orderkey
+            and l2.l_suppkey <> l1.l_suppkey
+    )
+    and not exists (
+        select
+            *
+        from
+            lineitem l3
+        where
+            l3.l_orderkey = l1.l_orderkey
+            and l3.l_suppkey <> l1.l_suppkey
+            and l3.l_receiptdate > l3.l_commitdate
+    )
+    and s_nationkey = n_nationkey
+    and n_name = 'SAUDI ARABIA'
+group by
+    s_name
+order by
+    numwait desc,
+    s_name
+limit 100
+*/
+
+source = supplier
+| join ON s_suppkey = l1.l_suppkey lineitem as l1
+| join ON o_orderkey = l1.l_orderkey orders
+| join ON s_nationkey = n_nationkey nation
+| where o_orderstatus = 'F'
+  and l1.l_receiptdate > l1.l_commitdate
+  and exists [
+    source = lineitem as l2
+    | where l2.l_orderkey = l1.l_orderkey
+      and l2.l_suppkey != l1.l_suppkey
+  ]
+  and not exists [
+    source = lineitem as l3
+    | where l3.l_orderkey = l1.l_orderkey
+      and l3.l_suppkey != l1.l_suppkey
+      and l3.l_receiptdate > l3.l_commitdate
+  ]
+  and n_name = 'SAUDI ARABIA'
+| stats count() as numwait by s_name
+| sort - numwait, s_name
+| head 100
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q22.ppl b/integ-test/src/integration/resources/tpch/q22.ppl
new file mode 100644
index 000000000..811308cb0
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q22.ppl
@@ -0,0 +1,58 @@
+/*
+select
+    cntrycode,
+    count(*) as numcust,
+    sum(c_acctbal) as totacctbal
+from
+    (
+        select
+            substring(c_phone, 1, 2) as cntrycode,
+            c_acctbal
+        from
+            customer
+        where
+            substring(c_phone, 1, 2) in
+                ('13', '31', '23', '29', '30', '18', '17')
+            and c_acctbal > (
+                select
+                    avg(c_acctbal)
+                from
+                    customer
+                where
+                    c_acctbal > 0.00
+                    and substring(c_phone, 1, 2) in
+                        ('13', '31', '23', '29', '30', '18', '17')
+            )
+            and not exists (
+                select
+                    *
+                from
+                    orders
+                where
+                    o_custkey = c_custkey
+            )
+    ) as custsale
+group by
+    cntrycode
+order by
+    cntrycode
+*/
+
+source = [
+  source = customer
+    | where substring(c_phone, 1, 2) in ('13', '31', '23', '29', '30', '18', '17')
+      and c_acctbal > [
+          source = customer
+          | where c_acctbal > 0.00
+            and substring(c_phone, 1, 2) in ('13', '31', '23', '29', '30', '18', '17')
+          | stats avg(c_acctbal)
+        ]
+      and not exists [
+          source = orders
+          | where o_custkey = c_custkey
+        ]
+    | eval cntrycode = substring(c_phone, 1, 2)
+    | fields cntrycode, c_acctbal
+  ] as custsale
+| stats count() as numcust, sum(c_acctbal) as totacctbal by cntrycode
+| sort cntrycode
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q3.ppl b/integ-test/src/integration/resources/tpch/q3.ppl
new file mode 100644
index 000000000..0ece358ab
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q3.ppl
@@ -0,0 +1,33 @@
+/*
+select
+    l_orderkey,
+    sum(l_extendedprice * (1 - l_discount)) as revenue,
+    o_orderdate,
+    o_shippriority
+from
+    customer,
+    orders,
+    lineitem
+where
+    c_mktsegment = 'BUILDING'
+    and c_custkey = o_custkey
+    and l_orderkey = o_orderkey
+    and o_orderdate < date '1995-03-15'
+    and l_shipdate > date '1995-03-15'
+group by
+    l_orderkey,
+    o_orderdate,
+    o_shippriority
+order by
+    revenue desc,
+    o_orderdate
+limit 10
+*/
+
+source = customer
+| join ON c_custkey = o_custkey orders
+| join ON l_orderkey = o_orderkey lineitem
+| where c_mktsegment = 'BUILDING' AND o_orderdate < date('1995-03-15') AND l_shipdate > date('1995-03-15')
+| stats sum(l_extendedprice * (1 - l_discount)) as revenue by l_orderkey, o_orderdate, o_shippriority
+| sort - revenue, o_orderdate
+| head 10
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q4.ppl b/integ-test/src/integration/resources/tpch/q4.ppl
new file mode 100644
index 000000000..cc01bda7d
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q4.ppl
@@ -0,0 +1,33 @@
+/*
+select
+    o_orderpriority,
+    count(*) as order_count
+from
+    orders
+where
+    o_orderdate >= date '1993-07-01'
+    and o_orderdate < date '1993-07-01' + interval '3' month
+    and exists (
+        select
+            *
+        from
+            lineitem
+        where
+            l_orderkey = o_orderkey
+            and l_commitdate < l_receiptdate
+    )
+group by
+    o_orderpriority
+order by
+    o_orderpriority
+*/
+
+source = orders
+| where o_orderdate >= date('1993-07-01')
+  and o_orderdate < date_add(date('1993-07-01'), interval 3 month)
+  and exists [
+    source = lineitem
+    | where l_orderkey = o_orderkey and l_commitdate < l_receiptdate
+  ]
+| stats count() as order_count by o_orderpriority
+| sort o_orderpriority
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q5.ppl b/integ-test/src/integration/resources/tpch/q5.ppl
new file mode 100644
index 000000000..4761b0365
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q5.ppl
@@ -0,0 +1,36 @@
+/*
+select
+    n_name,
+    sum(l_extendedprice * (1 - l_discount)) as revenue
+from
+    customer,
+    orders,
+    lineitem,
+    supplier,
+    nation,
+    region
+where
+    c_custkey = o_custkey
+    and l_orderkey = o_orderkey
+    and l_suppkey = s_suppkey
+    and c_nationkey = s_nationkey
+    and s_nationkey = n_nationkey
+    and n_regionkey = r_regionkey
+    and r_name = 'ASIA'
+    and o_orderdate >= date '1994-01-01'
+    and o_orderdate < date '1994-01-01' + interval '1' year
+group by
+    n_name
+order by
+    revenue desc
+*/
+
+source = customer
+| join ON c_custkey = o_custkey orders
+| join ON l_orderkey = o_orderkey lineitem
+| join ON l_suppkey = s_suppkey AND c_nationkey = s_nationkey supplier
+| join ON s_nationkey = n_nationkey nation
+| join ON n_regionkey = r_regionkey region
+| where r_name = 'ASIA' AND o_orderdate >= date('1994-01-01') AND o_orderdate < date_add(date('1994-01-01'), interval 1 year)
+| stats sum(l_extendedprice * (1 - l_discount)) as revenue by n_name
+| sort - revenue
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q6.ppl b/integ-test/src/integration/resources/tpch/q6.ppl
new file mode 100644
index 000000000..6a77877c3
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q6.ppl
@@ -0,0 +1,18 @@
+/*
+select
+    sum(l_extendedprice * l_discount) as revenue
+from
+    lineitem
+where
+    l_shipdate >= date '1994-01-01'
+    and l_shipdate < date '1994-01-01' + interval '1' year
+    and l_discount between .06 - 0.01 and .06 + 0.01
+    and l_quantity < 24
+*/
+
+source = lineitem
+| where l_shipdate >= date('1994-01-01')
+  and l_shipdate < adddate(date('1994-01-01'), 365)
+  and l_discount between .06 - 0.01 and .06 + 0.01
+  and l_quantity < 24
+| stats sum(l_extendedprice * l_discount) as revenue
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q7.ppl b/integ-test/src/integration/resources/tpch/q7.ppl
new file mode 100644
index 000000000..ceda602b3
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q7.ppl
@@ -0,0 +1,56 @@
+/*
+select
+    supp_nation,
+    cust_nation,
+    l_year,
+    sum(volume) as revenue
+from
+    (
+        select
+            n1.n_name as supp_nation,
+            n2.n_name as cust_nation,
+            year(l_shipdate) as l_year,
+            l_extendedprice * (1 - l_discount) as volume
+        from
+            supplier,
+            lineitem,
+            orders,
+            customer,
+            nation n1,
+            nation n2
+        where
+            s_suppkey = l_suppkey
+            and o_orderkey = l_orderkey
+            and c_custkey = o_custkey
+            and s_nationkey = n1.n_nationkey
+            and c_nationkey = n2.n_nationkey
+            and (
+                (n1.n_name = 'FRANCE' and n2.n_name = 'GERMANY')
+                or (n1.n_name = 'GERMANY' and n2.n_name = 'FRANCE')
+            )
+            and l_shipdate between date '1995-01-01' and date '1996-12-31'
+    ) as shipping
+group by
+    supp_nation,
+    cust_nation,
+    l_year
+order by
+    supp_nation,
+    cust_nation,
+    l_year
+*/
+
+source = [
+    source = supplier
+    | join ON s_suppkey = l_suppkey lineitem
+    | join ON o_orderkey = l_orderkey orders
+    | join ON c_custkey = o_custkey customer
+    | join ON s_nationkey = n1.n_nationkey nation as n1
+    | join ON c_nationkey = n2.n_nationkey nation as n2
+    | where l_shipdate between date('1995-01-01') and date('1996-12-31')
+        and n1.n_name = 'FRANCE' and n2.n_name = 'GERMANY' or n1.n_name = 'GERMANY' and n2.n_name = 'FRANCE'
+    | eval supp_nation = n1.n_name, cust_nation = n2.n_name, l_year = year(l_shipdate), volume = l_extendedprice * (1 - l_discount)
+    | fields supp_nation, cust_nation, l_year, volume
+  ] as shipping
+| stats sum(volume) as revenue by supp_nation, cust_nation, l_year
+| sort supp_nation, cust_nation, l_year
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q8.ppl b/integ-test/src/integration/resources/tpch/q8.ppl
new file mode 100644
index 000000000..a73c7f7c3
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q8.ppl
@@ -0,0 +1,60 @@
+/*
+select
+    o_year,
+    sum(case
+        when nation = 'BRAZIL' then volume
+        else 0
+    end) / sum(volume) as mkt_share
+from
+    (
+        select
+            year(o_orderdate) as o_year,
+            l_extendedprice * (1 - l_discount) as volume,
+            n2.n_name as nation
+        from
+            part,
+            supplier,
+            lineitem,
+            orders,
+            customer,
+            nation n1,
+            nation n2,
+            region
+        where
+            p_partkey = l_partkey
+            and s_suppkey = l_suppkey
+            and l_orderkey = o_orderkey
+            and o_custkey = c_custkey
+            and c_nationkey = n1.n_nationkey
+            and n1.n_regionkey = r_regionkey
+            and r_name = 'AMERICA'
+            and s_nationkey = n2.n_nationkey
+            and o_orderdate between date '1995-01-01' and date '1996-12-31'
+            and p_type = 'ECONOMY ANODIZED STEEL'
+    ) as all_nations
+group by
+    o_year
+order by
+    o_year
+*/
+
+source = [
+    source = part
+    | join ON p_partkey = l_partkey lineitem
+    | join ON s_suppkey = l_suppkey supplier
+    | join ON l_orderkey = o_orderkey orders
+    | join ON o_custkey = c_custkey customer
+    | join ON c_nationkey = n1.n_nationkey nation as n1
+    | join ON s_nationkey = n2.n_nationkey nation as n2
+    | join ON n1.n_regionkey = r_regionkey region
+    | where r_name = 'AMERICA' AND p_type = 'ECONOMY ANODIZED STEEL'
+      and o_orderdate between date('1995-01-01') and date('1996-12-31')
+    | eval o_year = year(o_orderdate)
+    | eval volume = l_extendedprice * (1 - l_discount)
+    | eval nation = n2.n_name
+    | fields o_year, volume, nation
+  ] as all_nations
+| stats sum(case(nation = 'BRAZIL', volume else 0)) as sum_case, sum(volume) as sum_volume by o_year
+| eval mkt_share = sum_case / sum_volume
+| fields mkt_share, o_year
+| sort o_year
\ No newline at end of file
diff --git a/integ-test/src/integration/resources/tpch/q9.ppl b/integ-test/src/integration/resources/tpch/q9.ppl
new file mode 100644
index 000000000..7692afd74
--- /dev/null
+++ b/integ-test/src/integration/resources/tpch/q9.ppl
@@ -0,0 +1,50 @@
+/*
+select
+    nation,
+    o_year,
+    sum(amount) as sum_profit
+from
+    (
+        select
+            n_name as nation,
+            year(o_orderdate) as o_year,
+            l_extendedprice * (1 - l_discount) - ps_supplycost * l_quantity as amount
+        from
+            part,
+            supplier,
+            lineitem,
+            partsupp,
+            orders,
+            nation
+        where
+            s_suppkey = l_suppkey
+            and ps_suppkey = l_suppkey
+            and ps_partkey = l_partkey
+            and p_partkey = l_partkey
+            and o_orderkey = l_orderkey
+            and s_nationkey = n_nationkey
+            and p_name like '%green%'
+    ) as profit
+group by
+    nation,
+    o_year
+order by
+    nation,
+    o_year desc
+*/
+
+source = [
+    source = part
+    | join ON p_partkey = l_partkey lineitem
+    | join ON s_suppkey = l_suppkey supplier
+    | join ON ps_partkey = l_partkey and ps_suppkey = l_suppkey partsupp
+    | join ON o_orderkey = l_orderkey orders
+    | join ON s_nationkey = n_nationkey nation
+    | where like(p_name, '%green%')
+    | eval nation = n_name
+    | eval o_year = year(o_orderdate)
+    | eval amount = l_extendedprice * (1 - l_discount) - ps_supplycost * l_quantity
+    | fields nation, o_year, amount
+  ] as profit
+| stats sum(amount) as sum_profit by nation, o_year
+| sort nation, - o_year
\ No newline at end of file
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryBase.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryBase.scala
new file mode 100644
index 000000000..fb14210e9
--- /dev/null
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryBase.scala
@@ -0,0 +1,177 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.flint.spark.ppl.tpch
+
+import org.opensearch.flint.spark.ppl.FlintPPLSuite
+
+import org.apache.spark.SparkConf
+import org.apache.spark.sql.catalyst.TableIdentifier
+import org.apache.spark.sql.catalyst.expressions.codegen.{ByteCodeStats, CodeFormatter, CodeGenerator}
+import org.apache.spark.sql.catalyst.rules.RuleExecutor
+import org.apache.spark.sql.catalyst.util.DateTimeConstants.NANOS_PER_SECOND
+import org.apache.spark.sql.execution.{SparkPlan, WholeStageCodegenExec}
+import org.apache.spark.sql.internal.SQLConf
+
+trait TPCHQueryBase extends FlintPPLSuite {
+
+  override protected def sparkConf: SparkConf = {
+    super.sparkConf.set(SQLConf.MAX_TO_STRING_FIELDS.key, Int.MaxValue.toString)
+  }
+
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+    RuleExecutor.resetMetrics()
+    CodeGenerator.resetCompileTime()
+    WholeStageCodegenExec.resetCodeGenTime()
+    tpchCreateTable.values.foreach { ppl =>
+      sql(ppl)
+    }
+  }
+
+  override def afterAll(): Unit = {
+    try {
+      tpchCreateTable.keys.foreach { tableName =>
+        spark.sessionState.catalog.dropTable(TableIdentifier(tableName), true, true)
+      }
+      // For debugging dump some statistics about how much time was spent in various optimizer rules
+      // code generation, and compilation.
+      logWarning(RuleExecutor.dumpTimeSpent())
+      val codeGenTime = WholeStageCodegenExec.codeGenTime.toDouble / NANOS_PER_SECOND
+      val compileTime = CodeGenerator.compileTime.toDouble / NANOS_PER_SECOND
+      val codegenInfo =
+        s"""
+           |=== Metrics of Whole-stage Codegen ===
+           |Total code generation time: $codeGenTime seconds
+           |Total compile time: $compileTime seconds
+         """.stripMargin
+      logWarning(codegenInfo)
+      spark.sessionState.catalog.reset()
+    } finally {
+      super.afterAll()
+    }
+  }
+
+  def checkGeneratedCode(plan: SparkPlan, checkMethodCodeSize: Boolean = true): Unit = {
+    val codegenSubtrees = new collection.mutable.HashSet[WholeStageCodegenExec]()
+
+    def findSubtrees(plan: SparkPlan): Unit = {
+      plan foreach {
+        case s: WholeStageCodegenExec =>
+          codegenSubtrees += s
+        case s =>
+          s.subqueries.foreach(findSubtrees)
+      }
+    }
+
+    findSubtrees(plan)
+    codegenSubtrees.toSeq.foreach { subtree =>
+      val code = subtree.doCodeGen()._2
+      val (_, ByteCodeStats(maxMethodCodeSize, _, _)) =
+        try {
+          // Just check the generated code can be properly compiled
+          CodeGenerator.compile(code)
+        } catch {
+          case e: Exception =>
+            val msg =
+              s"""
+               |failed to compile:
+               |Subtree:
+               |$subtree
+               |Generated code:
+               |${CodeFormatter.format(code)}
+             """.stripMargin
+            throw new Exception(msg, e)
+        }
+
+      assert(
+        !checkMethodCodeSize ||
+          maxMethodCodeSize <= CodeGenerator.DEFAULT_JVM_HUGE_METHOD_LIMIT,
+        s"too long generated codes found in the WholeStageCodegenExec subtree (id=${subtree.id}) " +
+          s"and JIT optimization might not work:\n${subtree.treeString}")
+    }
+  }
+
+  val tpchCreateTable = Map(
+    "orders" ->
+      """
+        |CREATE TABLE `orders` (
+        |`o_orderkey` BIGINT, `o_custkey` BIGINT, `o_orderstatus` STRING,
+        |`o_totalprice` DECIMAL(10,0), `o_orderdate` DATE, `o_orderpriority` STRING,
+        |`o_clerk` STRING, `o_shippriority` INT, `o_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "nation" ->
+      """
+        |CREATE TABLE `nation` (
+        |`n_nationkey` BIGINT, `n_name` STRING, `n_regionkey` BIGINT, `n_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "region" ->
+      """
+        |CREATE TABLE `region` (
+        |`r_regionkey` BIGINT, `r_name` STRING, `r_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "part" ->
+      """
+        |CREATE TABLE `part` (`p_partkey` BIGINT, `p_name` STRING, `p_mfgr` STRING,
+        |`p_brand` STRING, `p_type` STRING, `p_size` INT, `p_container` STRING,
+        |`p_retailprice` DECIMAL(10,0), `p_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "partsupp" ->
+      """
+        |CREATE TABLE `partsupp` (`ps_partkey` BIGINT, `ps_suppkey` BIGINT,
+        |`ps_availqty` INT, `ps_supplycost` DECIMAL(10,0), `ps_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "customer" ->
+      """
+        |CREATE TABLE `customer` (`c_custkey` BIGINT, `c_name` STRING, `c_address` STRING,
+        |`c_nationkey` BIGINT, `c_phone` STRING, `c_acctbal` DECIMAL(10,0),
+        |`c_mktsegment` STRING, `c_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "supplier" ->
+      """
+        |CREATE TABLE `supplier` (`s_suppkey` BIGINT, `s_name` STRING, `s_address` STRING,
+        |`s_nationkey` BIGINT, `s_phone` STRING, `s_acctbal` DECIMAL(10,0), `s_comment` STRING)
+        |USING parquet
+      """.stripMargin,
+    "lineitem" ->
+      """
+        |CREATE TABLE `lineitem` (`l_orderkey` BIGINT, `l_partkey` BIGINT, `l_suppkey` BIGINT,
+        |`l_linenumber` INT, `l_quantity` DECIMAL(10,0), `l_extendedprice` DECIMAL(10,0),
+        |`l_discount` DECIMAL(10,0), `l_tax` DECIMAL(10,0), `l_returnflag` STRING,
+        |`l_linestatus` STRING, `l_shipdate` DATE, `l_commitdate` DATE, `l_receiptdate` DATE,
+        |`l_shipinstruct` STRING, `l_shipmode` STRING, `l_comment` STRING)
+        |USING parquet
+      """.stripMargin)
+
+  val tpchQueries = Seq(
+    "q1",
+    "q2",
+    "q3",
+    "q4",
+    "q5",
+    "q6",
+    "q7",
+    "q8",
+    "q9",
+    "q10",
+    "q11",
+    "q12",
+    "q13",
+    "q14",
+    "q15",
+    "q16",
+    "q17",
+    "q18",
+    "q19",
+    "q20",
+    "q21",
+    "q22")
+}
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryITSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryITSuite.scala
new file mode 100644
index 000000000..1b9681618
--- /dev/null
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/tpch/TPCHQueryITSuite.scala
@@ -0,0 +1,43 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.flint.spark.ppl.tpch
+
+import org.opensearch.flint.spark.ppl.LogicalPlanTestUtils
+
+import org.apache.spark.sql.QueryTest
+import org.apache.spark.sql.catalyst.util.resourceToString
+import org.apache.spark.sql.streaming.StreamTest
+
+class TPCHQueryITSuite
+    extends QueryTest
+    with LogicalPlanTestUtils
+    with TPCHQueryBase
+    with StreamTest {
+
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+  }
+
+  protected override def afterEach(): Unit = {
+    super.afterEach()
+    // Stop all streaming jobs if any
+    spark.streams.active.foreach { job =>
+      job.stop()
+      job.awaitTermination()
+    }
+  }
+
+  tpchQueries.foreach { name =>
+    val queryString = resourceToString(
+      s"tpch/$name.ppl",
+      classLoader = Thread.currentThread().getContextClassLoader)
+    test(name) {
+      // check the plans can be properly generated
+      val plan = sql(queryString).queryExecution.executedPlan
+      checkGeneratedCode(plan)
+    }
+  }
+}

From 4303057aad2c0edd0ae2c75ef48bee81cd4bb7af Mon Sep 17 00:00:00 2001
From: YANGDB <yang.db.dev@gmail.com>
Date: Wed, 6 Nov 2024 18:25:25 -0800
Subject: [PATCH 4/4] Expand ppl command (#868)

* add expand command

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* add expand command with visitor

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* create unit / integration tests

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update expand tests

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* add tests

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update doc

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update docs with examples

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update scala style

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update with additional test case
remove outer generator

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update with additional test case
remove outer generator

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

* update documentation

Signed-off-by: YANGDB <yang.db.dev@gmail.com>

---------

Signed-off-by: YANGDB <yang.db.dev@gmail.com>
---
 docs/ppl-lang/PPL-Example-Commands.md         |  37 ++-
 docs/ppl-lang/README.md                       |   2 +
 docs/ppl-lang/ppl-expand-command.md           |  45 +++
 .../flint/spark/FlintSparkSuite.scala         |  22 ++
 .../ppl/FlintSparkPPLExpandITSuite.scala      | 255 ++++++++++++++++
 .../src/main/antlr4/OpenSearchPPLLexer.g4     |   1 +
 .../src/main/antlr4/OpenSearchPPLParser.g4    |   6 +
 .../sql/ast/AbstractNodeVisitor.java          |   4 +
 .../org/opensearch/sql/ast/tree/Expand.java   |  44 +++
 .../org/opensearch/sql/ast/tree/Flatten.java  |   4 +-
 .../sql/ppl/CatalystQueryPlanVisitor.java     |  25 +-
 .../opensearch/sql/ppl/parser/AstBuilder.java |   6 +
 ...PlanExpandCommandTranslatorTestSuite.scala | 281 ++++++++++++++++++
 13 files changed, 716 insertions(+), 16 deletions(-)
 create mode 100644 docs/ppl-lang/ppl-expand-command.md
 create mode 100644 integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLExpandITSuite.scala
 create mode 100644 ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Expand.java
 create mode 100644 ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanExpandCommandTranslatorTestSuite.scala

diff --git a/docs/ppl-lang/PPL-Example-Commands.md b/docs/ppl-lang/PPL-Example-Commands.md
index e80f8c906..4ea564111 100644
--- a/docs/ppl-lang/PPL-Example-Commands.md
+++ b/docs/ppl-lang/PPL-Example-Commands.md
@@ -441,8 +441,30 @@ Assumptions: `a`, `b` are fields of table outer, `c`, `d` are fields of table in
 
 _- **Limitation: another command usage of (relation) subquery is in `appendcols` commands which is unsupported**_
 
----
-#### Experimental Commands:
+
+#### **fillnull**
+[See additional command details](ppl-fillnull-command.md)
+```sql
+   -  `source=accounts | fillnull fields status_code=101`
+   -  `source=accounts | fillnull fields request_path='/not_found', timestamp='*'`
+    - `source=accounts | fillnull using field1=101`
+    - `source=accounts | fillnull using field1=concat(field2, field3), field4=2*pi()*field5`
+    - `source=accounts | fillnull using field1=concat(field2, field3), field4=2*pi()*field5, field6 = 'N/A'`
+```
+
+#### **expand**
+[See additional command details](ppl-expand-command.md)
+```sql
+   -  `source = table | expand field_with_array as array_list`
+   -  `source = table | expand employee | stats max(salary) as max by state, company`
+   -  `source = table | expand employee as worker | stats max(salary) as max by state, company`
+   -  `source = table | expand employee as worker | eval bonus = salary * 3 | fields worker, bonus`
+   -  `source = table | expand employee | parse description '(?<email>.+@.+)' | fields employee, email`
+   -  `source = table | eval array=json_array(1, 2, 3) | expand array as uid | fields name, occupation, uid`
+   -  `source = table | expand multi_valueA as multiA | expand multi_valueB as multiB`
+```
+
+#### Correlation Commands:
 [See additional command details](ppl-correlation-command.md)
 
 ```sql
@@ -454,14 +476,3 @@ _- **Limitation: another command usage of (relation) subquery is in `appendcols`
 > ppl-correlation-command is an experimental command - it may be removed in future versions
 
 ---
-### Planned Commands:
-
-#### **fillnull**
-[See additional command details](ppl-fillnull-command.md)
-```sql
-   -  `source=accounts | fillnull fields status_code=101`
-   -  `source=accounts | fillnull fields request_path='/not_found', timestamp='*'`
-    - `source=accounts | fillnull using field1=101`
-    - `source=accounts | fillnull using field1=concat(field2, field3), field4=2*pi()*field5`
-    - `source=accounts | fillnull using field1=concat(field2, field3), field4=2*pi()*field5, field6 = 'N/A'`
-```
diff --git a/docs/ppl-lang/README.md b/docs/ppl-lang/README.md
index ef186e5f2..d72c973be 100644
--- a/docs/ppl-lang/README.md
+++ b/docs/ppl-lang/README.md
@@ -71,6 +71,8 @@ For additional examples see the next [documentation](PPL-Example-Commands.md).
     - [`correlation commands`](ppl-correlation-command.md)
   
     - [`trendline commands`](ppl-trendline-command.md)
+  
+    - [`expand commands`](ppl-expand-command.md)
 
 * **Functions**
 
diff --git a/docs/ppl-lang/ppl-expand-command.md b/docs/ppl-lang/ppl-expand-command.md
new file mode 100644
index 000000000..144c0aafa
--- /dev/null
+++ b/docs/ppl-lang/ppl-expand-command.md
@@ -0,0 +1,45 @@
+## PPL `expand` command
+
+### Description
+Using `expand` command to flatten a field of type:
+- `Array<Any>`
+- `Map<Any>`
+
+
+### Syntax
+`expand <field> [As alias]`
+
+* field: to be expanded (exploded). The field must be of supported type.
+* alias: Optional to be expanded as the name to be used instead of the original field name
+
+### Usage Guidelines
+The expand command produces a row for each element in the specified array or map field, where:
+- Array elements become individual rows.
+- Map key-value pairs are broken into separate rows, with each key-value represented as a row.
+
+- When an alias is provided, the exploded values are represented under the alias instead of the original field name.
+- This can be used in combination with other commands, such as stats, eval, and parse to manipulate or extract data post-expansion.
+
+### Examples:
+-  `source = table | expand employee | stats max(salary) as max by state, company`
+-  `source = table | expand employee as worker | stats max(salary) as max by state, company`
+-  `source = table | expand employee as worker | eval bonus = salary * 3 | fields worker, bonus`
+-  `source = table | expand employee | parse description '(?<email>.+@.+)' | fields employee, email`
+-  `source = table | eval array=json_array(1, 2, 3) | expand array as uid | fields name, occupation, uid`
+-  `source = table | expand multi_valueA as multiA | expand multi_valueB as multiB`
+
+- Expand command can be used in combination with other commands such as `eval`, `stats` and more
+- Using multiple expand commands will create a cartesian product of all the internal elements within each composite array or map 
+
+### Effective SQL push-down query
+The expand command is translated into an equivalent SQL operation using LATERAL VIEW explode, allowing for efficient exploding of arrays or maps at the SQL query level.
+
+```sql
+SELECT customer exploded_productId
+FROM table
+LATERAL VIEW explode(productId) AS exploded_productId
+```
+Where the `explode` command offers the following functionality:
+- it is a column operation that returns a new column
+- it creates a new row for every element in the exploded column
+- internal `null`s are ignored as part of the exploded field (no row is created/exploded for null) 
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/FlintSparkSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/FlintSparkSuite.scala
index c53eee548..68d370791 100644
--- a/integ-test/src/integration/scala/org/opensearch/flint/spark/FlintSparkSuite.scala
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/FlintSparkSuite.scala
@@ -559,6 +559,28 @@ trait FlintSparkSuite extends QueryTest with FlintSuite with OpenSearchSuite wit
            |""".stripMargin)
   }
 
+  protected def createMultiColumnArrayTable(testTable: String): Unit = {
+    // CSV doesn't support struct field
+    sql(s"""
+           | CREATE TABLE $testTable
+           | (
+           |   int_col INT,
+           |   multi_valueA Array<STRUCT<name: STRING, value: INT>>,
+           |   multi_valueB Array<STRUCT<name: STRING, value: INT>>
+           | )
+           | USING JSON
+           |""".stripMargin)
+
+    sql(s"""
+           | INSERT INTO $testTable
+           | VALUES
+           | ( 1, array(STRUCT("1_one", 1), STRUCT(null, 11), STRUCT("1_three", null)),  array(STRUCT("2_Monday", 2), null) ),
+           | ( 2, array(STRUCT("2_Monday", 2), null) , array(STRUCT("3_third", 3), STRUCT("3_4th", 4)) ),
+           | ( 3, array(STRUCT("3_third", 3), STRUCT("3_4th", 4)) , array(STRUCT("1_one", 1))),
+           | ( 4, null, array(STRUCT("1_one", 1)))
+           |""".stripMargin)
+  }
+
   protected def createTableIssue112(testTable: String): Unit = {
     sql(s"""
            | CREATE TABLE $testTable (
diff --git a/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLExpandITSuite.scala b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLExpandITSuite.scala
new file mode 100644
index 000000000..f0404bf7b
--- /dev/null
+++ b/integ-test/src/integration/scala/org/opensearch/flint/spark/ppl/FlintSparkPPLExpandITSuite.scala
@@ -0,0 +1,255 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.opensearch.flint.spark.ppl
+
+import java.nio.file.Files
+
+import scala.collection.mutable
+
+import org.opensearch.sql.ppl.utils.DataTypeTransformer.seq
+
+import org.apache.spark.sql.{QueryTest, Row}
+import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedFunction, UnresolvedRelation, UnresolvedStar}
+import org.apache.spark.sql.catalyst.expressions.{Alias, EqualTo, Explode, GeneratorOuter, Literal, Or}
+import org.apache.spark.sql.catalyst.plans.logical._
+import org.apache.spark.sql.streaming.StreamTest
+
+class FlintSparkPPLExpandITSuite
+    extends QueryTest
+    with LogicalPlanTestUtils
+    with FlintPPLSuite
+    with StreamTest {
+
+  private val testTable = "flint_ppl_test"
+  private val occupationTable = "spark_catalog.default.flint_ppl_flat_table_test"
+  private val structNestedTable = "spark_catalog.default.flint_ppl_struct_nested_test"
+  private val structTable = "spark_catalog.default.flint_ppl_struct_test"
+  private val multiValueTable = "spark_catalog.default.flint_ppl_multi_value_test"
+  private val multiArraysTable = "spark_catalog.default.flint_ppl_multi_array_test"
+  private val tempFile = Files.createTempFile("jsonTestData", ".json")
+
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+
+    // Create test table
+    createNestedJsonContentTable(tempFile, testTable)
+    createOccupationTable(occupationTable)
+    createStructNestedTable(structNestedTable)
+    createStructTable(structTable)
+    createMultiValueStructTable(multiValueTable)
+    createMultiColumnArrayTable(multiArraysTable)
+  }
+
+  protected override def afterEach(): Unit = {
+    super.afterEach()
+    // Stop all streaming jobs if any
+    spark.streams.active.foreach { job =>
+      job.stop()
+      job.awaitTermination()
+    }
+  }
+
+  override def afterAll(): Unit = {
+    super.afterAll()
+    Files.deleteIfExists(tempFile)
+  }
+
+  test("expand for eval field of an array") {
+    val frame = sql(
+      s""" source = $occupationTable | eval array=json_array(1, 2, 3) | expand array as uid | fields name, occupation, uid
+       """.stripMargin)
+
+    val results: Array[Row] = frame.collect()
+    val expectedResults: Array[Row] = Array(
+      Row("Jake", "Engineer", 1),
+      Row("Jake", "Engineer", 2),
+      Row("Jake", "Engineer", 3),
+      Row("Hello", "Artist", 1),
+      Row("Hello", "Artist", 2),
+      Row("Hello", "Artist", 3),
+      Row("John", "Doctor", 1),
+      Row("John", "Doctor", 2),
+      Row("John", "Doctor", 3),
+      Row("David", "Doctor", 1),
+      Row("David", "Doctor", 2),
+      Row("David", "Doctor", 3),
+      Row("David", "Unemployed", 1),
+      Row("David", "Unemployed", 2),
+      Row("David", "Unemployed", 3),
+      Row("Jane", "Scientist", 1),
+      Row("Jane", "Scientist", 2),
+      Row("Jane", "Scientist", 3))
+
+    // Compare the results
+    assert(results.toSet == expectedResults.toSet)
+
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    // expected plan
+    val table = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_flat_table_test"))
+    val jsonFunc =
+      UnresolvedFunction("array", Seq(Literal(1), Literal(2), Literal(3)), isDistinct = false)
+    val aliasA = Alias(jsonFunc, "array")()
+    val project = Project(seq(UnresolvedStar(None), aliasA), table)
+    val generate = Generate(
+      Explode(UnresolvedAttribute("array")),
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("uid")),
+      project)
+    val dropSourceColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("array")), generate)
+    val expectedPlan = Project(
+      seq(
+        UnresolvedAttribute("name"),
+        UnresolvedAttribute("occupation"),
+        UnresolvedAttribute("uid")),
+      dropSourceColumn)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+  }
+
+  test("expand for structs") {
+    val frame = sql(
+      s""" source = $multiValueTable | expand multi_value AS exploded_multi_value | fields exploded_multi_value
+       """.stripMargin)
+
+    val results: Array[Row] = frame.collect()
+    val expectedResults: Array[Row] = Array(
+      Row(Row("1_one", 1)),
+      Row(Row(null, 11)),
+      Row(Row("1_three", null)),
+      Row(Row("2_Monday", 2)),
+      Row(null),
+      Row(Row("3_third", 3)),
+      Row(Row("3_4th", 4)),
+      Row(null))
+    // Compare the results
+    assert(results.toSet == expectedResults.toSet)
+
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    // expected plan
+    val table = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_multi_value_test"))
+    val generate = Generate(
+      Explode(UnresolvedAttribute("multi_value")),
+      seq(),
+      outer = false,
+      None,
+      seq(UnresolvedAttribute("exploded_multi_value")),
+      table)
+    val dropSourceColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("multi_value")), generate)
+    val expectedPlan = Project(Seq(UnresolvedAttribute("exploded_multi_value")), dropSourceColumn)
+    comparePlans(logicalPlan, expectedPlan, checkAnalysis = false)
+  }
+
+  test("expand for array of structs") {
+    val frame = sql(s"""
+                       | source = $testTable
+                       | | where country = 'England' or country = 'Poland'
+                       | | expand bridges 
+                       | | fields bridges
+                       | """.stripMargin)
+
+    val results: Array[Row] = frame.collect()
+    val expectedResults: Array[Row] = Array(
+      Row(mutable.WrappedArray.make(Array(Row(801, "Tower Bridge"), Row(928, "London Bridge")))),
+      Row(mutable.WrappedArray.make(Array(Row(801, "Tower Bridge"), Row(928, "London Bridge"))))
+      // Row(null)) -> in case of outerGenerator = GeneratorOuter(Explode(UnresolvedAttribute("bridges"))) it will include the `null` row
+    )
+
+    // Compare the results
+    assert(results.toSet == expectedResults.toSet)
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    val table = UnresolvedRelation(Seq("flint_ppl_test"))
+    val filter = Filter(
+      Or(
+        EqualTo(UnresolvedAttribute("country"), Literal("England")),
+        EqualTo(UnresolvedAttribute("country"), Literal("Poland"))),
+      table)
+    val generate =
+      Generate(Explode(UnresolvedAttribute("bridges")), seq(), outer = false, None, seq(), filter)
+    val expectedPlan = Project(Seq(UnresolvedAttribute("bridges")), generate)
+    comparePlans(logicalPlan, expectedPlan, checkAnalysis = false)
+  }
+
+  test("expand for array of structs with alias") {
+    val frame = sql(s"""
+                       | source = $testTable
+                       | | where country = 'England' 
+                       | | expand bridges as britishBridges
+                       | | fields britishBridges
+                       | """.stripMargin)
+
+    val results: Array[Row] = frame.collect()
+    val expectedResults: Array[Row] = Array(
+      Row(Row(801, "Tower Bridge")),
+      Row(Row(928, "London Bridge")),
+      Row(Row(801, "Tower Bridge")),
+      Row(Row(928, "London Bridge")))
+    // Compare the results
+    assert(results.toSet == expectedResults.toSet)
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    val table = UnresolvedRelation(Seq("flint_ppl_test"))
+    val filter = Filter(EqualTo(UnresolvedAttribute("country"), Literal("England")), table)
+    val generate = Generate(
+      Explode(UnresolvedAttribute("bridges")),
+      seq(),
+      outer = false,
+      None,
+      seq(UnresolvedAttribute("britishBridges")),
+      filter)
+    val dropColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("bridges")), generate)
+    val expectedPlan = Project(Seq(UnresolvedAttribute("britishBridges")), dropColumn)
+
+    comparePlans(logicalPlan, expectedPlan, checkAnalysis = false)
+  }
+
+  test("expand multi columns array table") {
+    val frame = sql(s"""
+                       | source = $multiArraysTable
+                       | | expand multi_valueA as multiA
+                       | | expand multi_valueB as multiB
+                       | """.stripMargin)
+
+    val results: Array[Row] = frame.collect()
+    val expectedResults: Array[Row] = Array(
+      Row(1, Row("1_one", 1), Row("2_Monday", 2)),
+      Row(1, Row("1_one", 1), null),
+      Row(1, Row(null, 11), Row("2_Monday", 2)),
+      Row(1, Row(null, 11), null),
+      Row(1, Row("1_three", null), Row("2_Monday", 2)),
+      Row(1, Row("1_three", null), null),
+      Row(2, Row("2_Monday", 2), Row("3_third", 3)),
+      Row(2, Row("2_Monday", 2), Row("3_4th", 4)),
+      Row(2, null, Row("3_third", 3)),
+      Row(2, null, Row("3_4th", 4)),
+      Row(3, Row("3_third", 3), Row("1_one", 1)),
+      Row(3, Row("3_4th", 4), Row("1_one", 1)))
+    // Compare the results
+    assert(results.toSet == expectedResults.toSet)
+
+    val logicalPlan: LogicalPlan = frame.queryExecution.logical
+    val table = UnresolvedRelation(Seq("spark_catalog", "default", "flint_ppl_multi_array_test"))
+    val generatorA = Explode(UnresolvedAttribute("multi_valueA"))
+    val generateA =
+      Generate(generatorA, seq(), false, None, seq(UnresolvedAttribute("multiA")), table)
+    val dropSourceColumnA =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("multi_valueA")), generateA)
+    val generatorB = Explode(UnresolvedAttribute("multi_valueB"))
+    val generateB = Generate(
+      generatorB,
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("multiB")),
+      dropSourceColumnA)
+    val dropSourceColumnB =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("multi_valueB")), generateB)
+    val expectedPlan = Project(seq(UnresolvedStar(None)), dropSourceColumnB)
+    comparePlans(expectedPlan, logicalPlan, checkAnalysis = false)
+
+  }
+}
diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
index 93efb2df1..2c3344b3c 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLLexer.g4
@@ -37,6 +37,7 @@ KMEANS:                             'KMEANS';
 AD:                                 'AD';
 ML:                                 'ML';
 FILLNULL:                           'FILLNULL';
+EXPAND:                             'EXPAND';
 FLATTEN:                            'FLATTEN';
 TRENDLINE:                          'TRENDLINE';
 
diff --git a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4 b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
index 123d1e15a..1cfd172f7 100644
--- a/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
+++ b/ppl-spark-integration/src/main/antlr4/OpenSearchPPLParser.g4
@@ -54,6 +54,7 @@ commands
    | fillnullCommand
    | fieldsummaryCommand
    | flattenCommand
+   | expandCommand
    | trendlineCommand
    ;
 
@@ -82,6 +83,7 @@ commandName
    | PATTERNS
    | LOOKUP
    | RENAME
+   | EXPAND
    | FILLNULL
    | FIELDSUMMARY
    | FLATTEN
@@ -250,6 +252,10 @@ fillnullCommand
    : expression
    ;
 
+expandCommand
+    : EXPAND fieldExpression (AS alias = qualifiedName)?
+    ;
+    
 flattenCommand
     : FLATTEN fieldExpression
     ;
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java
index 189d9084a..54e1205cb 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java
@@ -108,6 +108,10 @@ public T visitFilter(Filter node, C context) {
     return visitChildren(node, context);
   }
 
+  public T visitExpand(Expand node, C context) {
+    return visitChildren(node, context);
+  }
+
   public T visitLookup(Lookup node, C context) {
     return visitChildren(node, context);
   }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Expand.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Expand.java
new file mode 100644
index 000000000..0e164ccd7
--- /dev/null
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Expand.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.sql.ast.tree;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.opensearch.sql.ast.AbstractNodeVisitor;
+import org.opensearch.sql.ast.Node;
+import org.opensearch.sql.ast.expression.Field;
+import org.opensearch.sql.ast.expression.UnresolvedAttribute;
+import org.opensearch.sql.ast.expression.UnresolvedExpression;
+
+import java.util.List;
+import java.util.Optional;
+
+/** Logical plan node of Expand */
+@RequiredArgsConstructor
+public class Expand extends UnresolvedPlan {
+  private UnresolvedPlan child;
+
+  @Getter
+  private final Field field;
+  @Getter
+  private final Optional<UnresolvedExpression> alias;
+  
+  @Override
+  public Expand attach(UnresolvedPlan child) {
+    this.child = child;
+    return this;
+  }
+
+  @Override
+  public List<? extends Node> getChild() {
+    return child == null ? List.of() : List.of(child);
+  }
+
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitExpand(this, context);
+  }
+}
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Flatten.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Flatten.java
index e31fbb6e3..9c57d2adf 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Flatten.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ast/tree/Flatten.java
@@ -14,7 +14,7 @@ public class Flatten extends UnresolvedPlan {
     private UnresolvedPlan child;
 
     @Getter
-    private final Field fieldToBeFlattened;
+    private final Field field;
 
     @Override
     public UnresolvedPlan attach(UnresolvedPlan child) {
@@ -26,7 +26,7 @@ public UnresolvedPlan attach(UnresolvedPlan child) {
     public List<? extends Node> getChild() {
         return child == null ? List.of() : List.of(child);
     }
-
+    
     @Override
     public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
         return nodeVisitor.visitFlatten(this, context);
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
index a43378480..d2ee46ae6 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/CatalystQueryPlanVisitor.java
@@ -11,6 +11,7 @@
 import org.apache.spark.sql.catalyst.analysis.UnresolvedStar$;
 import org.apache.spark.sql.catalyst.expressions.Ascending$;
 import org.apache.spark.sql.catalyst.expressions.Descending$;
+import org.apache.spark.sql.catalyst.expressions.Explode;
 import org.apache.spark.sql.catalyst.expressions.Expression;
 import org.apache.spark.sql.catalyst.expressions.GeneratorOuter;
 import org.apache.spark.sql.catalyst.expressions.In$;
@@ -93,6 +94,7 @@
 
 import static java.util.Collections.emptyList;
 import static java.util.List.of;
+import static org.opensearch.sql.ppl.CatalystPlanContext.findRelation;
 import static org.opensearch.sql.ppl.utils.DataTypeTransformer.seq;
 import static org.opensearch.sql.ppl.utils.DedupeTransformer.retainMultipleDuplicateEvents;
 import static org.opensearch.sql.ppl.utils.DedupeTransformer.retainMultipleDuplicateEventsAndKeepEmpty;
@@ -460,13 +462,34 @@ public LogicalPlan visitFlatten(Flatten flatten, CatalystPlanContext context) {
             // Create an UnresolvedStar for all-fields projection
             context.getNamedParseExpressions().push(UnresolvedStar$.MODULE$.apply(Option.<Seq<String>>empty()));
         }
-        Expression field = visitExpression(flatten.getFieldToBeFlattened(), context);
+        Expression field = visitExpression(flatten.getField(), context);
         context.retainAllNamedParseExpressions(p -> (NamedExpression) p);
         FlattenGenerator flattenGenerator = new FlattenGenerator(field);
         context.apply(p -> new Generate(new GeneratorOuter(flattenGenerator), seq(), true, (Option) None$.MODULE$, seq(), p));
         return context.apply(logicalPlan -> DataFrameDropColumns$.MODULE$.apply(seq(field), logicalPlan));
     }
 
+    @Override
+    public LogicalPlan visitExpand(org.opensearch.sql.ast.tree.Expand node, CatalystPlanContext context) {
+        node.getChild().get(0).accept(this, context);
+        if (context.getNamedParseExpressions().isEmpty()) {
+            // Create an UnresolvedStar for all-fields projection
+            context.getNamedParseExpressions().push(UnresolvedStar$.MODULE$.apply(Option.<Seq<String>>empty()));
+        }
+        Expression field = visitExpression(node.getField(), context);
+        Optional<Expression> alias = node.getAlias().map(aliasNode -> visitExpression(aliasNode, context));
+        context.retainAllNamedParseExpressions(p -> (NamedExpression) p);
+        Explode explodeGenerator = new Explode(field);
+        scala.collection.mutable.Seq outputs = alias.isEmpty() ? seq() : seq(alias.get());
+        if(alias.isEmpty())
+            return context.apply(p -> new Generate(explodeGenerator, seq(), false, (Option) None$.MODULE$, outputs, p));
+        else {
+            //in case an alias does appear - remove the original field from the returning columns
+            context.apply(p -> new Generate(explodeGenerator, seq(), false, (Option) None$.MODULE$, outputs, p));
+            return context.apply(logicalPlan -> DataFrameDropColumns$.MODULE$.apply(seq(field), logicalPlan));
+        }
+    }
+
     private void visitFieldList(List<Field> fieldList, CatalystPlanContext context) {
         fieldList.forEach(field -> visitExpression(field, context));
     }
diff --git a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
index 36a34cd06..f6581016f 100644
--- a/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
+++ b/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/parser/AstBuilder.java
@@ -131,6 +131,12 @@ public UnresolvedPlan visitWhereCommand(OpenSearchPPLParser.WhereCommandContext
     return new Filter(internalVisitExpression(ctx.logicalExpression()));
   }
 
+  @Override
+  public UnresolvedPlan visitExpandCommand(OpenSearchPPLParser.ExpandCommandContext ctx) {
+    return new Expand((Field) internalVisitExpression(ctx.fieldExpression()),
+            ctx.alias!=null ? Optional.of(internalVisitExpression(ctx.alias)) : Optional.empty());
+  }
+
   @Override
   public UnresolvedPlan visitCorrelateCommand(OpenSearchPPLParser.CorrelateCommandContext ctx) {
     return new Correlation(ctx.correlationType().getText(),
diff --git a/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanExpandCommandTranslatorTestSuite.scala b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanExpandCommandTranslatorTestSuite.scala
new file mode 100644
index 000000000..2acaac529
--- /dev/null
+++ b/ppl-spark-integration/src/test/scala/org/opensearch/flint/spark/ppl/PPLLogicalPlanExpandCommandTranslatorTestSuite.scala
@@ -0,0 +1,281 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.flint.spark.ppl
+
+import org.opensearch.flint.spark.FlattenGenerator
+import org.opensearch.flint.spark.ppl.PlaneUtils.plan
+import org.opensearch.sql.ppl.{CatalystPlanContext, CatalystQueryPlanVisitor}
+import org.opensearch.sql.ppl.utils.DataTypeTransformer.seq
+import org.scalatest.matchers.should.Matchers
+
+import org.apache.spark.SparkFunSuite
+import org.apache.spark.sql.catalyst.analysis.{UnresolvedAttribute, UnresolvedFunction, UnresolvedRelation, UnresolvedStar}
+import org.apache.spark.sql.catalyst.expressions.{Alias, Explode, GeneratorOuter, Literal, RegExpExtract}
+import org.apache.spark.sql.catalyst.plans.PlanTest
+import org.apache.spark.sql.catalyst.plans.logical.{Aggregate, DataFrameDropColumns, Generate, Project}
+import org.apache.spark.sql.types.IntegerType
+
+class PPLLogicalPlanExpandCommandTranslatorTestSuite
+    extends SparkFunSuite
+    with PlanTest
+    with LogicalPlanTestUtils
+    with Matchers {
+
+  private val planTransformer = new CatalystQueryPlanVisitor()
+  private val pplParser = new PPLSyntaxParser()
+
+  test("test expand only field") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(plan(pplParser, "source=relation | expand field_with_array"), context)
+
+    val relation = UnresolvedRelation(Seq("relation"))
+    val generator = Explode(UnresolvedAttribute("field_with_array"))
+    val generate = Generate(generator, seq(), false, None, seq(), relation)
+    val expectedPlan = Project(seq(UnresolvedStar(None)), generate)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("expand multi columns array table") {
+    val context = new CatalystPlanContext
+    val logPlan = planTransformer.visit(
+      plan(
+        pplParser,
+        s"""
+         | source = table
+         | | expand multi_valueA as multiA
+         | | expand multi_valueB as multiB
+         | """.stripMargin),
+      context)
+
+    val relation = UnresolvedRelation(Seq("table"))
+    val generatorA = Explode(UnresolvedAttribute("multi_valueA"))
+    val generateA =
+      Generate(generatorA, seq(), false, None, seq(UnresolvedAttribute("multiA")), relation)
+    val dropSourceColumnA =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("multi_valueA")), generateA)
+    val generatorB = Explode(UnresolvedAttribute("multi_valueB"))
+    val generateB = Generate(
+      generatorB,
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("multiB")),
+      dropSourceColumnA)
+    val dropSourceColumnB =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("multi_valueB")), generateB)
+    val expectedPlan = Project(seq(UnresolvedStar(None)), dropSourceColumnB)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand on array field which is eval array=json_array") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(
+        plan(
+          pplParser,
+          "source = table | eval array=json_array(1, 2, 3) | expand array as uid | fields uid"),
+        context)
+
+    val relation = UnresolvedRelation(Seq("table"))
+    val jsonFunc =
+      UnresolvedFunction("array", Seq(Literal(1), Literal(2), Literal(3)), isDistinct = false)
+    val aliasA = Alias(jsonFunc, "array")()
+    val project = Project(seq(UnresolvedStar(None), aliasA), relation)
+    val generate = Generate(
+      Explode(UnresolvedAttribute("array")),
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("uid")),
+      project)
+    val dropSourceColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("array")), generate)
+    val expectedPlan = Project(seq(UnresolvedAttribute("uid")), dropSourceColumn)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand only field with alias") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(
+        plan(pplParser, "source=relation | expand field_with_array as array_list "),
+        context)
+
+    val relation = UnresolvedRelation(Seq("relation"))
+    val generate = Generate(
+      Explode(UnresolvedAttribute("field_with_array")),
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("array_list")),
+      relation)
+    val dropSourceColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("field_with_array")), generate)
+    val expectedPlan = Project(seq(UnresolvedStar(None)), dropSourceColumn)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and stats") {
+    val context = new CatalystPlanContext
+    val query =
+      "source = table | expand employee | stats max(salary) as max by state, company"
+    val logPlan =
+      planTransformer.visit(plan(pplParser, query), context)
+    val table = UnresolvedRelation(Seq("table"))
+    val generate =
+      Generate(Explode(UnresolvedAttribute("employee")), seq(), false, None, seq(), table)
+    val average = Alias(
+      UnresolvedFunction(seq("MAX"), seq(UnresolvedAttribute("salary")), false, None, false),
+      "max")()
+    val state = Alias(UnresolvedAttribute("state"), "state")()
+    val company = Alias(UnresolvedAttribute("company"), "company")()
+    val groupingState = Alias(UnresolvedAttribute("state"), "state")()
+    val groupingCompany = Alias(UnresolvedAttribute("company"), "company")()
+    val aggregate =
+      Aggregate(Seq(groupingState, groupingCompany), Seq(average, state, company), generate)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), aggregate)
+
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and stats with alias") {
+    val context = new CatalystPlanContext
+    val query =
+      "source = table | expand employee as workers | stats max(salary) as max by state, company"
+    val logPlan =
+      planTransformer.visit(plan(pplParser, query), context)
+    val table = UnresolvedRelation(Seq("table"))
+    val generate = Generate(
+      Explode(UnresolvedAttribute("employee")),
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("workers")),
+      table)
+    val dropSourceColumn = DataFrameDropColumns(Seq(UnresolvedAttribute("employee")), generate)
+    val average = Alias(
+      UnresolvedFunction(seq("MAX"), seq(UnresolvedAttribute("salary")), false, None, false),
+      "max")()
+    val state = Alias(UnresolvedAttribute("state"), "state")()
+    val company = Alias(UnresolvedAttribute("company"), "company")()
+    val groupingState = Alias(UnresolvedAttribute("state"), "state")()
+    val groupingCompany = Alias(UnresolvedAttribute("company"), "company")()
+    val aggregate = Aggregate(
+      Seq(groupingState, groupingCompany),
+      Seq(average, state, company),
+      dropSourceColumn)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), aggregate)
+
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and eval") {
+    val context = new CatalystPlanContext
+    val query = "source = table | expand employee | eval bonus = salary * 3"
+    val logPlan = planTransformer.visit(plan(pplParser, query), context)
+    val table = UnresolvedRelation(Seq("table"))
+    val generate =
+      Generate(Explode(UnresolvedAttribute("employee")), seq(), false, None, seq(), table)
+    val bonusProject = Project(
+      Seq(
+        UnresolvedStar(None),
+        Alias(
+          UnresolvedFunction(
+            "*",
+            Seq(UnresolvedAttribute("salary"), Literal(3, IntegerType)),
+            isDistinct = false),
+          "bonus")()),
+      generate)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), bonusProject)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and eval with fields and alias") {
+    val context = new CatalystPlanContext
+    val query =
+      "source = table | expand employee as worker | eval bonus = salary * 3 | fields worker, bonus "
+    val logPlan = planTransformer.visit(plan(pplParser, query), context)
+    val table = UnresolvedRelation(Seq("table"))
+    val generate = Generate(
+      Explode(UnresolvedAttribute("employee")),
+      seq(),
+      false,
+      None,
+      seq(UnresolvedAttribute("worker")),
+      table)
+    val dropSourceColumn =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("employee")), generate)
+    val bonusProject = Project(
+      Seq(
+        UnresolvedStar(None),
+        Alias(
+          UnresolvedFunction(
+            "*",
+            Seq(UnresolvedAttribute("salary"), Literal(3, IntegerType)),
+            isDistinct = false),
+          "bonus")()),
+      dropSourceColumn)
+    val expectedPlan =
+      Project(Seq(UnresolvedAttribute("worker"), UnresolvedAttribute("bonus")), bonusProject)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and parse and fields") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(
+        plan(
+          pplParser,
+          "source=table | expand employee | parse description '(?<email>.+@.+)' | fields employee, email"),
+        context)
+    val table = UnresolvedRelation(Seq("table"))
+    val generator =
+      Generate(Explode(UnresolvedAttribute("employee")), seq(), false, None, seq(), table)
+    val emailAlias =
+      Alias(
+        RegExpExtract(UnresolvedAttribute("description"), Literal("(?<email>.+@.+)"), Literal(1)),
+        "email")()
+    val parseProject = Project(
+      Seq(UnresolvedAttribute("description"), emailAlias, UnresolvedStar(None)),
+      generator)
+    val expectedPlan =
+      Project(Seq(UnresolvedAttribute("employee"), UnresolvedAttribute("email")), parseProject)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+  test("test expand and parse and flatten ") {
+    val context = new CatalystPlanContext
+    val logPlan =
+      planTransformer.visit(
+        plan(
+          pplParser,
+          "source=relation | expand employee | parse description '(?<email>.+@.+)' | flatten roles "),
+        context)
+    val table = UnresolvedRelation(Seq("relation"))
+    val generateEmployee =
+      Generate(Explode(UnresolvedAttribute("employee")), seq(), false, None, seq(), table)
+    val emailAlias =
+      Alias(
+        RegExpExtract(UnresolvedAttribute("description"), Literal("(?<email>.+@.+)"), Literal(1)),
+        "email")()
+    val parseProject = Project(
+      Seq(UnresolvedAttribute("description"), emailAlias, UnresolvedStar(None)),
+      generateEmployee)
+    val generateRoles = Generate(
+      GeneratorOuter(new FlattenGenerator(UnresolvedAttribute("roles"))),
+      seq(),
+      true,
+      None,
+      seq(),
+      parseProject)
+    val dropSourceColumnRoles =
+      DataFrameDropColumns(Seq(UnresolvedAttribute("roles")), generateRoles)
+    val expectedPlan = Project(Seq(UnresolvedStar(None)), dropSourceColumnRoles)
+    comparePlans(expectedPlan, logPlan, checkAnalysis = false)
+  }
+
+}