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Date: Wed, 11 Jun 2008 15:59:09 +0200
From: Kristian Waagan <Kristian.Waagan@Sun.COM>
Subject: Re: Speed of using Derby DB
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Thomas Nielsen wrote:
> vodarus vodarus wrote:
>>         PS does derby / javaDB have it's own forum?
>>
>>
>>     Do you mean outside this mailing list?
>>
>>
>> Yes. I think forum is more visual tool for communication than mail-list.
>>
> 
> If so, you can read the list using nabble (www.nabble.com) :)
> 
> Cheers,
> Thomas
> 
> PS:
> It *may* be that the reason for the slow execution is outdated index 
> cardinality statistics. Check out "CALL 
> SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE" either on nabble or in the 
> derby docs.

Vodarus,

Did you get around to try out the tip from Thomas?

If you first create the index and then load the data, the statistics can 
be badly outdated. If you first created the table, loaded the data and 
finally created the index you should be fine though.

Just curious, as we have seen reports of severe performance degradations 
because of this issue, which causes the optimizer to choose a bad plan.


regards,
-- 
Kristian


>