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https://issues.apache.org/jira/browse/DERBY-6226?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13666455#comment-13666455
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Tony Brusseau commented on DERBY-6226:
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I think there should be a test for:
select * from a where col1 = ? or (col2 = ? and col3 = ?)
where there are 2 indexes, one for col1 and one for (col2, col3) just to help
ensure that any fix isn't over specific to single column indexing.
> enhance optmizer to use multiple probes into multiple indexes to satisfy OR
> queries on different columns.
> ---------------------------------------------------------------------------------------------------------
>
> Key: DERBY-6226
> URL: https://issues.apache.org/jira/browse/DERBY-6226
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 10.8.3.1, 10.11.0.0
> Reporter: Mike Matrigali
>
> For queries of the type:
> select * from a where col1 = ? or col2 = ?
> and good indexes exist on col1 and col2 it would be optimal if derby could
> execute a plan that
> did an index scan first on the col1 index and then an index scan on col2
> index.
> Currently it looks like derby will do a full index scan if col1 and col2 are
> in any index, or a full table
> scan otherwise.
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