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From Dag.Wan...@Sun.COM (Dag H. Wanvik)
Subject Re: Slow Query
Date Mon, 04 May 2009 00:51:35 GMT
DaveG24 <dave4aries@gmail.com> writes:


> Actually, I have a pretty complicated query that runs fine in ij and takes
> about 1 second to return 0 rows.  When I start my Java application, point to
> the derby.jar that contains my database, and run the same query, it takes 42
> seconds to return 0 rows.  Needless to say, I'm perplexed.  I can tune
> queries in the database, but I've never had a fast query go so much slower
> from an application.
>
> My Java application is a standalone app, all running from a directory
> structure that contains the jars and the database.  It also contains jre
> 1.6, and the database is derby 10.5.1.1, running on Windows XP.
>
> So, it's not really a derby problem - I don't think - but I don't know how
> to attack it.  I thought I'd see if anyone out there has experienced
> anything like this.

If Derby chooses a different (less optimal) execution plan in the
second case, that could account for the difference.

Derby lets you retrieve the chosen execution plan, cf.
http://db.apache.org/derby/docs/10.5/tuning/ttundepth34375.html

Is the plan the same in the two cases?

Dag

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