[jira] [Updated] (HIVE-18490) Query with EXISTS and NOT EXISTS with non-equi predicate can produce wrong result

["Gopal V (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-18490?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Gopal V updated HIVE-18490:
---------------------------
    Component/s: CBO

> 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
>          Components: CBO
>            Reporter: Vineet Garg
>            Assignee: Vineet Garg
>            Priority: Critical
>             Fix For: 3.0.0
>
>         Attachments: HIVE-18490.1.patch, HIVE-18490.2.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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