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From Bryan Pendleton <bpendle...@amberpoint.com>
Subject Re: Large IN clause performance
Date Sun, 03 Sep 2006 16:12:02 GMT
> The existing code makes a lot of use of SQL "IN" clauses, where the term can
> often contains thousands of items.
> 
> This performs very badly on 10.1.3.1 - because it seems to ignore indexes
> and just use the min and max terms to do a table scan

I think this is DERBY-47, also logged as DERBY-713:

http://issues.apache.org/jira/browse/DERBY-47
http://issues.apache.org/jira/browse/DERBY-713

The JIRA issues have some discussion of possible alternate strategies and ways
to rewrite queries to get better performance, but I don't think there's any
easy solution available right now, sorry.

We'd love to have help in this area; perhaps you can consider helping to work
on possible implementations?

thanks,

bryan


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