[jira] Commented: (DERBY-4971) Query runs 10 times more slowly with optimizer turned ON

["Dag H. Wanvik (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DERBY-4971?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12981470#action_12981470 ] 

Dag H. Wanvik commented on DERBY-4971:
--------------------------------------

Does it make a difference if you update the statistics?

Cf. http://db.apache.org/derby/docs/10.7/ref/rrefupdatestatsproc.html

> Query runs 10 times more slowly with optimizer turned ON
> --------------------------------------------------------
>
>                 Key: DERBY-4971
>                 URL: https://issues.apache.org/jira/browse/DERBY-4971
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.7.1.1
>            Reporter: Chris Wilson
>         Attachments: optimizer-off.sql, optimizer-on.sql, rita.derby.zip
>
>
> Derby takes 10 times as long to execute the attached query on the attached database when the optimizer is allowed to choose its own join order.
> chris@fen-desktop2(tmp)$ cat ij 
> #!/bin/sh
> DERBY_DIR=/home/chris/.m2/repository/org/apache/derby
> DERBY_VER=10.7.1.1
> DERBY_JAR=$DERBY_DIR/derby/$DERBY_VER/derby-$DERBY_VER.jar
> TOOLS_JAR=$DERBY_DIR/derbytools/$DERBY_VER/derbytools-$DERBY_VER.jar
> java -cp $DERBY_JAR:$TOOLS_JAR $OPTIONS org.apache.derby.tools.ij "$@"
> chris@fen-desktop2(tmp)$ time ./ij optimizer-on.sql 
> ij version 10.7
> ij> connect 'jdbc:derby:;databaseName=/tmp/rita.derby;user=rita';
> ij> SELECT journey.transport_company AS journey_transport_provider, ...
> 1 row selected
> ij> quit;
> real	0m47.459s
> user	0m47.067s
> sys	0m0.344s
> chris@fen-desktop2(tmp)$ time ./ij optimizer-off.sql 
> ...
> real	0m3.913s
> user	0m4.100s
> sys	0m0.148s

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.