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new 1ffc76606b GH-46599: [C++][Doc][Parquet] Update supported types
documentation (#46620)
1ffc76606b is described below
commit 1ffc76606b632485d477db532ecc714e69cbb0b7
Author: Dewey Dunnington <[email protected]>
AuthorDate: Mon Jun 2 10:47:00 2025 -0500
GH-46599: [C++][Doc][Parquet] Update supported types documentation (#46620)
### Rationale for this change
We now support more types but the documentation suggested that some weren't
supported.
### What changes are included in this PR?
Documentation was updated to reflect the status of supported types.
### Are these changes tested?
No code changes!
### Are there any user-facing changes?
No
* GitHub Issue: #46599
Lead-authored-by: Dewey Dunnington <[email protected]>
Co-authored-by: Dewey Dunnington <[email protected]>
Co-authored-by: Antoine Pitrou <[email protected]>
Signed-off-by: Dewey Dunnington <[email protected]>
---
docs/source/cpp/parquet.rst | 86 +++++++++++++++++++++++++++------------------
1 file changed, 51 insertions(+), 35 deletions(-)
diff --git a/docs/source/cpp/parquet.rst b/docs/source/cpp/parquet.rst
index 421b051b1c..162e8db9da 100644
--- a/docs/source/cpp/parquet.rst
+++ b/docs/source/cpp/parquet.rst
@@ -450,38 +450,46 @@ Logical types
Specific logical types can override the default Arrow type mapping for a given
physical type.
-+-------------------+-----------------------------+----------------------------+---------+
-| Logical type | Physical type | Mapped Arrow type
| Notes |
-+===================+=============================+============================+=========+
-| NULL | Any | Null
| \(1) |
-+-------------------+-----------------------------+----------------------------+---------+
-| INT | INT32 | Int8 / UInt8 / Int16 /
| |
-| | | UInt16 / Int32 / UInt32
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| INT | INT64 | Int64 / UInt64
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| DECIMAL | INT32 / INT64 / BYTE_ARRAY | Decimal128 / Decimal256
| \(2) |
-| | / FIXED_LENGTH_BYTE_ARRAY |
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| DATE | INT32 | Date32
| \(3) |
-+-------------------+-----------------------------+----------------------------+---------+
-| TIME | INT32 | Time32 (milliseconds)
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| TIME | INT64 | Time64 (micro- or
| |
-| | | nanoseconds)
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| TIMESTAMP | INT64 | Timestamp (milli-, micro-
| |
-| | | or nanoseconds)
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| STRING | BYTE_ARRAY | String / LargeString /
| |
-| | | StringView
| |
-+-------------------+-----------------------------+----------------------------+---------+
-| LIST | Any | List
| \(4) |
-+-------------------+-----------------------------+----------------------------+---------+
-| MAP | Any | Map
| \(5) |
-+-------------------+-----------------------------+----------------------------+---------+
-| FLOAT16 | FIXED_LENGTH_BYTE_ARRAY | HalfFloat
| |
-+-------------------+-----------------------------+----------------------------+---------+
++-------------------+-----------------------------+------------------------------+-----------+
+| Logical type | Physical type | Mapped Arrow type
| Notes |
++===================+=============================+==============================+===========+
+| NULL | Any | Null
| \(1) |
++-------------------+-----------------------------+------------------------------+-----------+
+| INT | INT32 | Int8 / UInt8 / Int16 /
| |
+| | | UInt16 / Int32 / UInt32
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| INT | INT64 | Int64 / UInt64
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| DECIMAL | INT32 / INT64 / BYTE_ARRAY | Decimal128 / Decimal256
| \(2) |
+| | / FIXED_LENGTH_BYTE_ARRAY |
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| DATE | INT32 | Date32
| \(3) |
++-------------------+-----------------------------+------------------------------+-----------+
+| TIME | INT32 | Time32 (milliseconds)
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| TIME | INT64 | Time64 (micro- or
| |
+| | | nanoseconds)
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| TIMESTAMP | INT64 | Timestamp (milli-, micro-
| |
+| | | or nanoseconds)
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| STRING | BYTE_ARRAY | String / LargeString /
| |
+| | | StringView
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| LIST | Any | List
| \(4) |
++-------------------+-----------------------------+------------------------------+-----------+
+| MAP | Any | Map
| \(5) |
++-------------------+-----------------------------+------------------------------+-----------+
+| FLOAT16 | FIXED_LENGTH_BYTE_ARRAY | HalfFloat
| |
++-------------------+-----------------------------+------------------------------+-----------+
+| UUID | FIXED_LENGTH_BYTE_ARRAY | Extension (``arrow.uuid``)
| \(6) |
++-------------------+-----------------------------+------------------------------+-----------+
+| JSON | BYTE_ARRAY | Extension (``arrow.json``)
| \(6) |
++-------------------+-----------------------------+------------------------------+-----------+
+| GEOMETRY | BYTE_ARRAY | Extension
(``geoarrow.wkb``) | \(6) \(7) |
++-------------------+-----------------------------+------------------------------+-----------+
+| GEOGRAPHY | BYTE_ARRAY | Extension
(``geoarrow.wkb``) | \(6) \(7) |
++-------------------+-----------------------------+------------------------------+-----------+
* \(1) On the write side, the Parquet physical type INT32 is generated.
@@ -496,9 +504,14 @@ physical type.
in contradiction with the
`Parquet specification
<https://github.com/apache/parquet-format/blob/master/LogicalTypes.md#maps>`__.
-*Unsupported logical types:* JSON, BSON, UUID. If such a type is encountered
+* \(6) Requires that ``arrow_extensions_enabled`` in ``ArrowReaderProperties``
is ``true``.
+ When ``false``, the underlying storage type is read.
+
+* \(7) Requires that the ``geoarrow.wkb`` extension type is registered.
+
+*Unsupported logical types:* BSON. If such a type is encountered
when reading a Parquet file, the default physical type mapping is used (for
-example, a Parquet JSON column may be read as Arrow Binary or FixedSizeBinary).
+example, a Parquet BSON column may be read as Arrow Binary or FixedSizeBinary).
Converted types
~~~~~~~~~~~~~~~
@@ -513,7 +526,10 @@ Special cases
An Arrow Extension type is written out as its storage type. It can still
be recreated at read time using Parquet metadata (see "Roundtripping Arrow
-types" below).
+types" below). Some extension types have Parquet LogicalType equivalents
+(e.g., UUID, JSON, GEOMETRY, GEOGRAPHY). These are created automatically
+if the appropriate option is set in the ``ArrowReaderProperties`` even if
+there was no Arrow schema stored in the Parquet metadata.
An Arrow Dictionary type is written out as its value type. It can still
be recreated at read time using Parquet metadata (see "Roundtripping Arrow
