[
https://issues.apache.org/jira/browse/DERBY-4327?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13758991#comment-13758991
]
Dag H. Wanvik commented on DERBY-4327:
--------------------------------------
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDwQFjAA&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.56.6379%26rep%3Drep1%26type%3Dpdf&ei=3GUoUtbTN8uQ0QWh0oDYAw&usg=AFQjCNFme8BiQI59ZnxP68M6cnY0Pzr_cA&bvm=bv.51773540,d.d2k&cad=rja
> Implement optimizer support for bushy trees.
> --------------------------------------------
>
> Key: DERBY-4327
> URL: https://issues.apache.org/jira/browse/DERBY-4327
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Reporter: Rick Hillegas
> Labels: derby_triage10_10
>
> Currently, the optimizer only considers left-deep trees. For queries
> involving many tables, the best plan may be bushy. In this email thread, a
> user notes poor performance by Derby on queries involving 5 or more tables:
> http://www.nabble.com/Slow-performance-on-5-or-more-joins-in-a-star-schema-tt24708686.html
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
