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https://issues.apache.org/jira/browse/IMPALA-10929?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Daniel Becker resolved IMPALA-10929.
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Resolution: Duplicate
> Optimise memory usage of structs in tuples
> ------------------------------------------
>
> Key: IMPALA-10929
> URL: https://issues.apache.org/jira/browse/IMPALA-10929
> Project: IMPALA
> Issue Type: Improvement
> Components: Frontend
> Reporter: Daniel Becker
> Assignee: Daniel Becker
> Priority: Major
>
> If we have both a whole struct and one of its members (or a member of a
> member etc.) in the select list, the whole struct and the member are assigned
> to different slots in the tuple. We could use less memory if the member
> expression used the slot within the whole struct instead.
> Example:
> For the query
> {code:java}
> select id, outer_struct from functional_orc_def.complextypes_nested_structs;
> {code}
> the row size is 64B, while for
> {code:java}
> select id, outer_struct, outer_struct.inner_struct2 from
> functional_orc_def.complextypes_nested_structs;
> {code}
> it is 80B, although it should not need more memory.
> It is not limited to the select list, it should also work with where clauses
> etc., for example
> {code:java}
> select id, outer_struct from functional_orc_def.complextypes_nested_structs
> where outer_struct.inner_struct2.i > 1;
> {code}
> should also have a row size of 64B instead of 68B.
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