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From "Daniel John Debrunner (JIRA)" <derby-...@db.apache.org>
Subject [jira] Commented: (DERBY-573) Provider support for optimizer overrides in Derby.
Date Tue, 20 Sep 2005 16:55:29 GMT
    [ http://issues.apache.org/jira/browse/DERBY-573?page=comments#action_12330025 ] 

Daniel John Debrunner commented on DERBY-573:
---------------------------------------------

I don't believe that  we should assume that every multiple database application is going to
use a code generator, or that Derby's syntax should force application developers into using
one. It is possible to write an application that works against multiple databases, thus the
use of comments to provide hints seems a reasonable approach.

It may  make more sense for the lead-in to be something like DERBY-HINTS or DERBY-PROPERTIES
rather than the generic term PROPERTIES.

> Provider support for optimizer overrides in Derby.
> --------------------------------------------------
>
>          Key: DERBY-573
>          URL: http://issues.apache.org/jira/browse/DERBY-573
>      Project: Derby
>         Type: New Feature
>   Components: SQL
>     Versions: 10.2.0.0
>     Reporter: Mamta A. Satoor
>     Assignee: Mamta A. Satoor
>  Attachments: optimizeroverrides.html
>
> Derby's query optimizer usually makes the best choice of join order and access path.
The default join strategy ususally works the best too. However, there are some cases in which
user may want to override the optimizer or the default values. Providing support for optimizer
overrides will allow users to hand-tune the optimizer for queries. 

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