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Posted to derby-dev@db.apache.org by "Ramin Baradari (JIRA)" <ji...@apache.org> on 2013/08/23 16:06:52 UTC

[jira] [Issue Comment Deleted] (DERBY-4327) Implement optimizer support for bushy trees.

     [ https://issues.apache.org/jira/browse/DERBY-4327?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ramin Baradari updated DERBY-4327:
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    Comment: was deleted

(was: Sehr geehrte Damen und Herren,

vielen Dank für Ihre Nachricht. Ich bin ab 1. Oktober 2012 wieder im Haus. Meine E-Mails werden nicht weitergeleitet und erst dann beantwortet. In dringenden Fällen wenden Sie sich bitte an Robert Buchwald unter der E-Mail-Adresse r.buchwald@4flow.de.

Mit freundlichen Grüßen
Ramin Baradari


Dear Sir or Madam:

Thank you very much for your email. I will be out of the office until October 1, 2012. I will answer your email upon my return. Please note that your email will not be forwarded during this time. In urgent cases, please do not hesitate to contact Robert Buchwald, r.buchwald@4flow.com.

Best regards
Ramin Baradari
)
    
> 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

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