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https://issues.apache.org/jira/browse/HIVE-22888?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Denys Kuzmenko updated HIVE-22888:
----------------------------------
    Attachment: Lock Perf.pdf

> Rewrite checkLock inner select with JOIN operator
> -------------------------------------------------
>
>                 Key: HIVE-22888
>                 URL: https://issues.apache.org/jira/browse/HIVE-22888
>             Project: Hive
>          Issue Type: Improvement
>          Components: Locking
>            Reporter: Denys Kuzmenko
>            Assignee: Denys Kuzmenko
>            Priority: Major
>         Attachments: HIVE-22888.1.patch, HIVE-22888.2.patch, 
> HIVE-22888.3.patch, HIVE-22888.4.patch, HIVE-22888.5.patch, 
> HIVE-22888.6.patch, HIVE-22888.8.patch, Lock Perf.pdf
>
>
> - Created extra (db, tbl, part) index on HIVE_LOCKS table;
> - Replaced inner select under checkLocks using multiple IN statements with 
> JOIN operator; 
> generated query looks like :
> {code}
> SELECT LS.* FROM (
>     SELECT HL_LOCK_EXT_ID, HL_DB, HL_TABLE, HL_PARTITION, HL_LOCK_STATE, 
> HL_LOCK_TYPE FROM HIVE_LOCKS
>     WHERE HL_LOCK_EXT_ID < 333) LS
> INNER JOIN (
>     SELECT HL_DB, HL_TABLE, HL_PARTITION, HL_LOCK_TYPE FROM HIVE_LOCKS WHERE 
> HL_LOCK_EXT_ID = 333) LBC
> ON LS.HL_DB = LBC.HL_DB
>     AND (LS.HL_TABLE IS NULL OR LBC.HL_TABLE IS NULL OR LS.HL_TABLE = 
> LBC.HL_TABLE
>     AND (LS.HL_PARTITION IS NULL OR LBC.HL_PARTITION IS NULL OR 
> LS.HL_PARTITION = LBC.HL_PARTITION))
> WHERE  (LBC.HL_TXNID = 0 OR LS.HL_TXNID != LBC.HL_TXNID) 
>     AND (LBC.HL_LOCK_TYPE='e'
>            AND !(LS.HL_TABLE IS NULL AND LS.HL_LOCK_TYPE='r' AND LBC.HL_TABLE 
> IS NOT NULL )
>     OR LBC.HL_LOCK_TYPE='w' AND LS.HL_LOCK_TYPE IN ('w','e')
>     OR LBC.HL_LOCK_TYPE='r' AND LS.HL_LOCK_TYPE='e'
>            AND !(LS.HL_TABLE IS NOT NULL AND LBC.HL_TABLE IS NULL))
> LIMIT 1;
> {code}



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