db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew McIntyre (JIRA)" <derby-...@db.apache.org>
Subject [jira] Closed: (DERBY-772) Handle pushing IN predicates into UNIONs. This would allow use of index if present improving performance.
Date Mon, 24 Apr 2006 20:42:09 GMT
     [ http://issues.apache.org/jira/browse/DERBY-772?page=all ]
     
Andrew McIntyre closed DERBY-772:
---------------------------------

    Resolution: Fixed

> Handle pushing IN predicates into UNIONs. This would allow use of index if present improving
performance.
> ---------------------------------------------------------------------------------------------------------
>
>          Key: DERBY-772
>          URL: http://issues.apache.org/jira/browse/DERBY-772
>      Project: Derby
>         Type: Sub-task

>   Components: SQL
>     Versions: 10.0.2.0, 10.1.2.1, 10.2.0.0
>  Environment: generic
>     Reporter: Satheesh Bandaram
>      Fix For: 10.2.0.0, 10.1.2.2, 10.1.3.0
>  Attachments: DERBY-772.patch
>
> While fix for DERBY-649 allows pushing binary predicates into SELECT statements that
are underneath a UNOIN, it would also be good to allow IN operations to be pushed. Derby can
rewrite IN operations in a way to allow use of index, if present.
> Derby currently rewrites: REF IN (1, 2, 3) to REF >=1 and REF <=3 and hence would
allow use of index on REF, if present. Pushing this predicate into Union would allow use of
index on REF for queries like:
> Select * from 
>      (SELECT REF, NAME from T1 UNION ALL SELECT REF, NAME from t2)
> where REF IN (1,2,3)

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira


Mime
View raw message