fix(python, rust): check timestamp_ntz in nested fields, add check_ca…

…n_writestamp_ntz in pyarrow writer (#2443)

# Description
The nested fields weren't checked, which meant you could get a
timestampNtz in your schema but not have the reader/writer features set.
This check is now done recursively.

crates/core/src/operations/create.rs

@@ -235,16 +235,12 @@ impl CreateBuilder {
             )
         };
 
-        let contains_timestampntz = &self
-            .columns
-            .iter()
-            .any(|f| f.data_type() == &DataType::TIMESTAMPNTZ);
-
+        let contains_timestampntz = PROTOCOL.contains_timestampntz(&self.columns);
         // TODO configure more permissive versions based on configuration. Also how should this ideally be handled?
         // We set the lowest protocol we can, and if subsequent writes use newer features we update metadata?
 
         let (min_reader_version, min_writer_version, writer_features, reader_features) =
-            if *contains_timestampntz {
+            if contains_timestampntz {
                 let mut converted_writer_features = self
                     .configuration
                     .keys()

crates/core/src/operations/transaction/protocol.rs

@@ -4,7 +4,9 @@ use lazy_static::lazy_static;
 use once_cell::sync::Lazy;
 
 use super::{TableReference, TransactionError};
-use crate::kernel::{Action, DataType, EagerSnapshot, ReaderFeatures, Schema, WriterFeatures};
+use crate::kernel::{
+    Action, DataType, EagerSnapshot, ReaderFeatures, Schema, StructField, WriterFeatures,
+};
 use crate::protocol::DeltaOperation;
 use crate::table::state::DeltaTableState;
 
@@ -77,17 +79,30 @@ impl ProtocolChecker {
         Ok(())
     }
 
+    /// checks if table contains timestamp_ntz in any field including nested fields.
+    pub fn contains_timestampntz(&self, fields: &Vec<StructField>) -> bool {
+        fn check_vec_fields(fields: &Vec<StructField>) -> bool {
+            fields.iter().any(|f| _check_type(f.data_type()))
+        }
+
+        fn _check_type(dtype: &DataType) -> bool {
+            match dtype {
+                &DataType::TIMESTAMPNTZ => true,
+                DataType::Array(inner) => _check_type(inner.element_type()),
+                DataType::Struct(inner) => check_vec_fields(inner.fields()),
+                _ => false,
+            }
+        }
+        check_vec_fields(fields)
+    }
+
     /// Check can write_timestamp_ntz
     pub fn check_can_write_timestamp_ntz(
         &self,
         snapshot: &DeltaTableState,
         schema: &Schema,
     ) -> Result<(), TransactionError> {
-        let contains_timestampntz = schema
-            .fields()
-            .iter()
-            .any(|f| f.data_type() == &DataType::TIMESTAMPNTZ);
-
+        let contains_timestampntz = self.contains_timestampntz(schema.fields());
         let required_features: Option<&HashSet<WriterFeatures>> =
             match snapshot.protocol().min_writer_version {
                 0..=6 => None,

python/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "deltalake-python"
-version = "0.17.0"
+version = "0.17.1"
 authors = ["Qingping Hou <[email protected]>", "Will Jones <[email protected]>"]
 homepage = "https://github.com/delta-io/delta-rs"
 license = "Apache-2.0"

python/deltalake/_internal.pyi

@@ -154,6 +154,7 @@ class RawDeltaTable:
         custom_metadata: Optional[Dict[str, str]],
     ) -> None: ...
     def cleanup_metadata(self) -> None: ...
+    def check_can_write_timestamp_ntz(self, schema: pyarrow.Schema) -> None: ...
 
 def rust_core_version() -> str: ...
 def write_new_deltalake(

python/deltalake/writer.py

@@ -429,6 +429,7 @@ def visitor(written_file: Any) -> None:
             # We don't currently provide a way to set invariants
             # (and maybe never will), so only enforce if already exist.
             table_protocol = table.protocol()
+            table._table.check_can_write_timestamp_ntz(schema)
             if (
                 table_protocol.min_writer_version > MAX_SUPPORTED_PYARROW_WRITER_VERSION
                 or table_protocol.min_writer_version

python/src/lib.rs

@@ -33,7 +33,7 @@ use deltalake::operations::filesystem_check::FileSystemCheckBuilder;
 use deltalake::operations::merge::MergeBuilder;
 use deltalake::operations::optimize::{OptimizeBuilder, OptimizeType};
 use deltalake::operations::restore::RestoreBuilder;
-use deltalake::operations::transaction::{CommitBuilder, CommitProperties};
+use deltalake::operations::transaction::{CommitBuilder, CommitProperties, PROTOCOL};
 use deltalake::operations::update::UpdateBuilder;
 use deltalake::operations::vacuum::VacuumBuilder;
 use deltalake::parquet::basic::Compression;
@@ -175,6 +175,17 @@ impl RawDeltaTable {
         ))
     }
 
+    pub fn check_can_write_timestamp_ntz(&self, schema: PyArrowType<ArrowSchema>) -> PyResult<()> {
+        let schema: StructType = (&schema.0).try_into().map_err(PythonError::from)?;
+        Ok(PROTOCOL
+            .check_can_write_timestamp_ntz(
+                self._table.snapshot().map_err(PythonError::from)?,
+                &schema,
+            )
+            .map_err(|e| DeltaTableError::Generic(e.to_string()))
+            .map_err(PythonError::from)?)
+    }
+
     pub fn load_version(&mut self, version: i64) -> PyResult<()> {
         Ok(rt()
             .block_on(self._table.load_version(version))

python/tests/test_writer.py

@@ -1528,3 +1528,45 @@ def test_rust_decimal_cast(tmp_path: pathlib.Path):
         write_deltalake(
             tmp_path, data, mode="append", schema_mode="merge", engine="rust"
         )
+
+
+@pytest.mark.parametrize(
+    "array",
+    [
+        pa.array([[datetime(2010, 1, 1)]]),
+        pa.array([{"foo": datetime(2010, 1, 1)}]),
+        pa.array([{"foo": [[datetime(2010, 1, 1)]]}]),
+        pa.array([{"foo": [[{"foo": datetime(2010, 1, 1)}]]}]),
+    ],
+)
+def test_write_timestamp_ntz_nested(tmp_path: pathlib.Path, array: pa.array):
+    data = pa.table({"x": array})
+    write_deltalake(tmp_path, data, mode="append", engine="rust")
+
+    dt = DeltaTable(tmp_path)
+
+    protocol = dt.protocol()
+    assert protocol.min_reader_version == 3
+    assert protocol.min_writer_version == 7
+    assert protocol.reader_features == ["timestampNtz"]
+    assert protocol.writer_features == ["timestampNtz"]
+
+
+def test_write_timestamp_ntz_on_table_with_features_not_enabled(tmp_path: pathlib.Path):
+    data = pa.table({"x": pa.array(["foo"])})
+    write_deltalake(tmp_path, data, mode="append", engine="pyarrow")
+
+    dt = DeltaTable(tmp_path)
+
+    protocol = dt.protocol()
+    assert protocol.min_reader_version == 1
+    assert protocol.min_writer_version == 2
+
+    data = pa.table({"x": pa.array([datetime(2010, 1, 1)])})
+    with pytest.raises(
+        DeltaError,
+        match="Generic DeltaTable error: Writer features must be specified for writerversion >= 7, please specify: TimestampWithoutTimezone",
+    ):
+        write_deltalake(
+            tmp_path, data, mode="overwrite", engine="pyarrow", schema_mode="overwrite"
+        )