PARQUET-1928: Interpret Parquet INT96 type as FIXED[12] AVRO Schema

[anantdamle]

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Reading Parquet files in Apache Beam using ParquetIO uses AvroParquetReader causing it to throw IllegalArgumentException("INT96 not implemented and is deprecated")

Customers have large datasets which can't be reprocessed again to convert into a supported type. An easier approach would be to convert into a byte array of 12 bytes, that can then be interpreted by the developer in any way they want to interpret it.

This patch interprets the INT96 parquet type as a byte array of 12-bytes. the developer/user can then handle it appropriate to interpret into a timestamp or simple some bytes.

• [x ] My PR adds the following unit tests testParquetInt96AsFixed12AvroType and testParquetInt96DefaultFail

https://issues.apache.org/jira/browse/PARQUET-1928

[anantdamle]

Adding @rdblue @tomwhite for review

[anantdamle]

Gentle bump up

[gszadovszky]

Parquet community was against adding INT96 support to not to encourage our clients to use it. While I understand the requirement of supporting the already written types. (Meanwhile as parquet-avro did not support INT96 ever this change is required for developments of new functionalities depending on the deprecated INT96.)
Anyway, I am fine with this change but I do not really like that it works by default. What do you think about keeping the original behavior by default and introduce a configuration flag to switch it on? (See writeParquetUUID as an example.) This way we still not encourage the clients to use INT96 but have the option to do so if it is necessary.

[anantdamle]

thanks for the review. I have incorporated the changes requested.

[anantdamle]

@gszadovszky Thanks for the approval.
sorry for a noob question. What happens next? how does this PR get merged in master?

[gszadovszky]

@anantdamle, thank you for the contribution!
I will do it. Just usually wait 24 hours (because of the weekend this time a bit more) to give a chance for others to comment before it gets merged.

[anantdamle]

Thanks @gszadovszky, quick request to kindly squash and merge as there are 2 - useless commits to rectify my IDE's autochange to LICENSE comments.

[gszadovszky]

@anantdamle, our usual process is to squash all the changes related to one jira before merging. Thanks a lot for your contribution!