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https://issues.apache.org/jira/browse/HIVE-19040?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16416066#comment-16416066
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Aihua Xu commented on HIVE-19040:
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Thanks [~sershe] If HS2 and HMS run with the same version, there would be no
issue. Not sure if it's a valid assumption though since after the metastore
separation, HMS would be a standalone service which may upgrade on its own
schedule. Looks like we need to keep certain level of backward compatibility
and we are trying to keep HMS backward compatible, but this api will defeat
such intention. Do you think we will not support HS2 and HMS with different
versions?
> get_partitions_by_expr() implementation in HiveMetaStore causes backward
> incompatibility easily
> ------------------------------------------------------------------------------------------------
>
> Key: HIVE-19040
> URL: https://issues.apache.org/jira/browse/HIVE-19040
> Project: Hive
> Issue Type: Improvement
> Components: Standalone Metastore
> Affects Versions: 2.0.0
> Reporter: Aihua Xu
> Priority: Major
>
> In the HiveMetaStore implementation of {{public PartitionsByExprResult
> get_partitions_by_expr(PartitionsByExprRequest req) throws TException}} , an
> expression is serialized into byte array from the client side and passed
> through PartitionsByExprRequest. Then HMS will deserialize back into the
> expression and filter the partitions by it.
> Such partition filtering expression can contain various UDFs. If there are
> some changes to one of the UDFs between different Hive versions, HS2 on the
> older version will serialize the expression in old format which won't be able
> to be deserialized by HMS on the newer version. One example of that is,
> GenericUDFIn class adds {{transient}} to the field constantInSet which will
> cause such incompatibility.
> One approach I'm thinking of is, instead of converting the expression object
> to byte array, we can pass the expression string directly.
>
>
>
>
>
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