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https://issues.apache.org/jira/browse/HIVE-18490?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vineet Garg updated HIVE-18490:
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Status: Patch Available (was: Open)
> Query with EXISTS and NOT EXISTS with non-equi predicate can produce wrong
> result
> ---------------------------------------------------------------------------------
>
> Key: HIVE-18490
> URL: https://issues.apache.org/jira/browse/HIVE-18490
> Project: Hive
> Issue Type: Bug
> Reporter: Vineet Garg
> Assignee: Vineet Garg
> Priority: Critical
> Attachments: HIVE-18490.1.patch
>
>
> Queries such as following can produce wrong result
> {code:sql}
> select
> count(ws_order_number)
> from
> web_sales ws1
> where
> and exists (select *
> from web_sales ws2
> where ws1.ws_order_number = ws2.ws_order_number
> and ws1.ws_warehouse_sk <> ws2.ws_warehouse_sk)
> and not exists(select *
> from web_returns wr1
> where ws1.ws_order_number = wr1.wr_order_number);
> {code}
> This query is simplified version of tpcds query 94. Such queries are
> rewritten into LEFT SEMI JOIN and LEFT OUTER JOIN with residual
> predicate/filter (non-equi join key). Problem is that these joins are being
> merged, we shouldn't be merging since semi join has non-equi join filter.
> Basically the underlying issue is that if a query has multiple join with LEFT
> SEMI JOIN with non-equi join key it is being merged with other joins. Merge
> logic should check such cases and avoid merging.
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