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https://issues.apache.org/jira/browse/PHOENIX-943?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Maryann Xue updated PHOENIX-943:
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Attachment: 943.patch
In join queries, independent filter conditions (as opposed to cross-table
filter conditions) from WHERE clause of ON clause are pushed down to
corresponding join tables as pre-filter conditions when applicable (certain
restrictions apply to left/right outer joins).
If a join table is a sub-query (derived table), pushed-down pre-filters will
finally get combined and rewritten into the sub-query itself. But in some rare
cases like when the sub-query has a limit or the sub-query is a non-group-by
aggregate query, the rewrite approach would not work, so we do client-side or
server-side post filter on the sub-query result.
> Handle pushed down post-filters for subquery in joins with limit and
> non-groupby aggregation
> --------------------------------------------------------------------------------------------
>
> Key: PHOENIX-943
> URL: https://issues.apache.org/jira/browse/PHOENIX-943
> Project: Phoenix
> Issue Type: Sub-task
> Affects Versions: 3.0.0, 4.0.0, 5.0.0
> Reporter: Maryann Xue
> Assignee: Maryann Xue
> Priority: Minor
> Fix For: 3.0.0, 4.0.0, 5.0.0
>
> Attachments: 943.patch
>
> Original Estimate: 48h
> Remaining Estimate: 48h
>
> Support cases like:
> 1) select ... from A join (select id, b from T limit 10) as B on A.id = B.id
> where B.b = 'b'
> 2) select ... from A join (select count(*) c from T) as B on A.a = B.c where
> B.c > 10
> These 2 cases cannot be handled by SubselectRewriter#applyPostFilters(), thus
> JoinCompiler should compile post-filters into query-plans for subqueries.
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