sdf-jkl commented on PR #10417: URL: https://github.com/apache/arrow-rs/pull/10417#issuecomment-5060497142
Hi @HuaHuaY! Arrow Variant closely follows the Parquet Variant spec - https://github.com/apache/parquet-format/blob/master/VariantEncoding.md The arrow [primitive type mapping](https://arrow.apache.org/docs/format/CanonicalExtensions.html#primitive-type-mappings) you've linked is following the table from the spec here - https://github.com/apache/parquet-format/blob/master/VariantEncoding.md#encoding-types - It's about unshredded Variant. The shredding spec here - https://github.com/apache/parquet-format/blob/master/VariantShredding.md#shredded-value-types - lists which Parquet types should be mapped to each Variant type for shredding. | Variant Type | Parquet Physical Type | Parquet Logical Type | |-----------------------------|-----------------------------------|--------------------------| ... | int8 | INT32 | INT(8, true) | | int16 | INT32 | INT(16, true) | | int32 | INT32 | | | int64 | INT64 | | ... Here Int* Variant types have to be represented by signed integers in Parquet -> we use signed int arrow arrays to store them. cc @klion26 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
