diff --git a/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/result/MongoDocument.scala b/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/result/MongoDocument.scala
index 3cd5008cd1..c151053027 100644
--- a/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/result/MongoDocument.scala
+++ b/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/result/MongoDocument.scala
@@ -9,6 +9,7 @@ import org.bson.Document
 
 import java.net.URI
 import java.util.Date
+import scala.collection.mutable
 
 /**
   * MongoDocument provides an implementation of VirtualDocument for MongoDB.
@@ -25,6 +26,12 @@ class MongoDocument[T >: Null <: AnyRef](
     var fromDocument: Document => T
 ) extends VirtualDocument[T] {
 
+  var previousCount: mutable.Map[String, Int] = mutable.Map()
+  var previousNumStats: mutable.Map[String, Map[String, Double]] = mutable.Map()
+  var previousDateStats: mutable.Map[String, Map[String, Date]] = mutable.Map()
+  var previousCatStats: mutable.Map[String, Map[String, Int]] = mutable.Map()
+  var previousReachedLimit: Boolean = false
+
   /**
     * The batch size for committing items to the MongoDB collection.
     */
@@ -143,11 +150,115 @@ class MongoDocument[T >: Null <: AnyRef](
     collectionMgr.getCount
   }
 
-  def getNumericColStats: Map[String, Map[String, Double]] =
-    collectionMgr.calculateNumericStats()
+  def getNumericColStats: Map[String, Map[String, Double]] = {
+    val offset: Int = previousCount.getOrElse("numeric_offset", 0)
+    val currentResult: Map[String, Map[String, Double]] =
+      collectionMgr.calculateNumericStats(offset)
+
+    currentResult.keys.foreach(field => {
+      val (prevMin, prevMax, prevMean) =
+        (
+          previousNumStats.getOrElse(field, Map("min" -> Double.MaxValue))("min"),
+          previousNumStats.getOrElse(field, Map("max" -> Double.MinValue))("max"),
+          previousNumStats.getOrElse(field, Map("mean" -> 0.0))("mean")
+        )
+
+      val (minValue, maxValue, meanValue, count) =
+        (
+          currentResult(field)("min"),
+          currentResult(field)("max"),
+          currentResult(field)("mean"),
+          currentResult(field)("count")
+        )
+
+      val newMin = Math.min(prevMin, minValue)
+      val newMax = Math.max(prevMax, maxValue)
+      val newMean = (prevMean * offset + meanValue * count) / (offset + count)
+
+      previousNumStats.update(field, Map("min" -> newMin, "max" -> newMax, "mean" -> newMean))
+      previousCount.update("numeric_offset", offset + count.toInt)
+    })
+
+    previousNumStats.toMap
+  }
+
+  def getDateColStats: Map[String, Map[String, Date]] = {
+    val offset: Int = previousCount.getOrElse("date_offset", 0)
+    val currentResult: Map[String, Map[String, Any]] = collectionMgr.calculateDateStats(offset)
+
+    currentResult.keys.foreach(field => {
+      val (prevMin, prevMax) =
+        (
+          previousDateStats
+            .getOrElse(field, Map("min" -> new java.util.Date(Long.MaxValue)))("min"),
+          previousDateStats.getOrElse(field, Map("max" -> new java.util.Date(Long.MinValue)))("max")
+        )
+
+      val (minValue: java.util.Date, maxValue: java.util.Date, count: Int) =
+        (currentResult(field)("min"), currentResult(field)("max"), currentResult(field)("count"))
+
+      val newMin: java.util.Date = if (minValue.before(prevMin)) minValue else prevMin
+      val newMax: java.util.Date = if (maxValue.after(prevMax)) maxValue else prevMax
 
-  def getDateColStats: Map[String, Map[String, Date]] = collectionMgr.calculateDateStats()
+      previousDateStats.update(field, Map("min" -> newMin, "max" -> newMax))
+      previousCount.update("date_offset", offset + count)
+    })
 
-  def getCategoricalStats: Map[String, Map[String, Map[String, Integer]]] =
-    collectionMgr.calculateCategoricalStats()
+    previousDateStats.toMap
+  }
+
+  def getCategoricalStats: Map[String, Map[String, Any]] = {
+    val offset: Int = previousCount.getOrElse("category_offset", 0)
+    val (currentResult: Map[String, Map[String, Int]], ifReachedLimit: Boolean) =
+      collectionMgr.calculateCategoricalStats(offset)
+    val result: mutable.Map[String, Map[String, Any]] = mutable.Map()
+
+    currentResult.keys.foreach(field => {
+      val fieldResult: mutable.Map[String, Any] = mutable.Map()
+      val count: Int = currentResult(field).values.sum
+      val newCatCounts: mutable.Map[String, Int] = mutable.Map()
+
+      currentResult(field).keys.foreach(category => {
+        try {
+          val prevCatCounts: Int = previousCatStats(field)(category)
+          newCatCounts.put(category, prevCatCounts + currentResult(field)(category))
+        } catch {
+          case e: NoSuchElementException =>
+            newCatCounts.put(category, 0 + currentResult(field)(category))
+        }
+      })
+
+      previousCatStats.update(field, newCatCounts.toMap)
+      previousCount.update("category_offset", offset + count)
+      previousReachedLimit = ifReachedLimit || previousReachedLimit
+
+      val top2 = previousCatStats(field).toSeq.sortBy(-_._2).take(2).map(_._1)
+      top2.size match {
+        case 2 =>
+          fieldResult("firstCat") = if (top2.head != null) top2.head else "NULL"
+          fieldResult("secondCat") = if (top2(1) != null) top2(1) else "NULL"
+          val first =
+            (previousCatStats(field)(top2.head).toDouble / (offset + count).toDouble) * 100
+          val second =
+            (previousCatStats(field)(top2(1)).toDouble / (offset + count).toDouble) * 100
+          fieldResult("firstPercent") = first
+          fieldResult("secondPercent") = second
+          fieldResult("other") = 100 - first - second
+          fieldResult("reachedLimit") = if (previousReachedLimit) 1 else 0
+        case 1 =>
+          fieldResult("firstCat") = if (top2.head != null) top2.head else "NULL"
+          fieldResult("secondCat") = ""
+          fieldResult("firstPercent") =
+            (previousCatStats(field)(top2.head).toDouble / (offset + count).toDouble) * 100
+          fieldResult("secondPercent") = 0
+          fieldResult("other") = 0
+          fieldResult("reachedLimit") = if (previousReachedLimit) 1 else 0
+        case _ => None
+      }
+
+      if (fieldResult.nonEmpty) result(field) = fieldResult.toMap
+    })
+
+    result.toMap
+  }
 }
diff --git a/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/util/mongo/MongoCollectionManager.scala b/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/util/mongo/MongoCollectionManager.scala
index b3f650450f..2d1c925c1c 100644
--- a/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/util/mongo/MongoCollectionManager.scala
+++ b/core/workflow-core/src/main/scala/edu/uci/ics/amber/core/storage/util/mongo/MongoCollectionManager.scala
@@ -37,7 +37,7 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
   /**
     * Calculate numeric statistics (min, max, mean) for numeric fields.
     */
-  def calculateNumericStats(): Map[String, Map[String, Double]] = {
+  def calculateNumericStats(offset: Int): Map[String, Map[String, Double]] = {
     val numericFields = detectNumericFields()
 
     numericFields.flatMap { field =>
@@ -48,8 +48,10 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
         .append("minValue", new Document("$min", "$" + field))
         .append("maxValue", new Document("$max", "$" + field))
         .append("meanValue", new Document("$avg", "$" + field))
+        .append("count", new Document("$sum", 1))
 
       val pipeline = Seq(
+        new Document("$skip", offset),
         new Document("$project", projection),
         new Document("$group", groupDoc)
       )
@@ -60,7 +62,8 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
         val stats = Map(
           "min" -> doc.get("minValue").asInstanceOf[Number].doubleValue(),
           "max" -> doc.get("maxValue").asInstanceOf[Number].doubleValue(),
-          "mean" -> doc.get("meanValue").asInstanceOf[Number].doubleValue()
+          "mean" -> doc.get("meanValue").asInstanceOf[Number].doubleValue(),
+          "count" -> doc.get("count").asInstanceOf[Number].doubleValue()
         )
         Some(field -> stats)
       } else {
@@ -72,7 +75,7 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
   /**
     * Calculate date statistics (min, max) for date fields.
     */
-  def calculateDateStats(): Map[String, Map[String, Date]] = {
+  def calculateDateStats(offset: Int): Map[String, Map[String, Any]] = {
     val dateFields = detectDateFields()
 
     dateFields.flatMap { field =>
@@ -82,8 +85,10 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
       val groupDoc = new Document("_id", null)
         .append("minValue", new Document("$min", "$" + field))
         .append("maxValue", new Document("$max", "$" + field))
+        .append("count", new Document("$sum", 1))
 
       val pipeline = Seq(
+        new Document("$skip", offset),
         new Document("$project", projection),
         new Document("$group", groupDoc)
       )
@@ -93,7 +98,8 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
         val doc = result.head
         val stats = Map(
           "min" -> doc.get("minValue").asInstanceOf[Date],
-          "max" -> doc.get("maxValue").asInstanceOf[Date]
+          "max" -> doc.get("maxValue").asInstanceOf[Date],
+          "count" -> doc.get("count").asInstanceOf[Number].intValue()
         )
         Some(field -> stats)
       } else {
@@ -103,26 +109,33 @@ class MongoCollectionManager(collection: MongoCollection[Document]) {
   }
 
   /**
-    * Calculate categorical statistics (value counts) for categorical fields.
+    * Calculate categorical statistics (value percentages) for categorical fields.
     */
-  def calculateCategoricalStats(): Map[String, Map[String, Map[String, Integer]]] = {
+  def calculateCategoricalStats(offset: Int): (Map[String, Map[String, Int]], Boolean) = {
     val categoricalFields = detectCategoricalFields()
+    var reachedLimit: Boolean = false
+
+    (
+      categoricalFields.flatMap { field =>
+        val pipeline = Seq(
+          new Document("$skip", offset),
+          Aggregates.group("$" + field, com.mongodb.client.model.Accumulators.sum("count", 1)),
+          Aggregates.sort(Sorts.descending("count")),
+          Aggregates.limit(1000)
+        )
 
-    categoricalFields.flatMap { field =>
-      val pipeline = Seq(
-        Aggregates.group("$" + field, com.mongodb.client.model.Accumulators.sum("count", 1)),
-        Aggregates.sort(Sorts.descending("count")),
-        Aggregates.limit(1000)
-      )
-
-      val result = collection.aggregate(pipeline.asJava).iterator().asScala.toList
-      if (result.nonEmpty) {
-        val counts = result.map(doc => doc.getString("_id") -> doc.getInteger("count")).toMap
-        Some(field -> Map("counts" -> counts))
-      } else {
-        None
-      }
-    }.toMap
+        val result = collection.aggregate(pipeline.asJava).iterator().asScala.toList
+        if (result.nonEmpty) {
+          val counts =
+            result.map(doc => doc.getString("_id") -> doc.getInteger("count").toInt).toMap
+          reachedLimit = result.size >= 1000
+          Some(field -> counts)
+        } else {
+          None
+        }
+      }.toMap,
+      reachedLimit
+    )
   }
 
   /**