db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Army <qoz...@gmail.com>
Subject Re: Trouble accessing read only DB with 10.1 (created and accessed fine with 10.0)
Date Thu, 06 Jul 2006 15:44:46 GMT
Leslie Software wrote:
> My larger database went from 2.8Mb to 1.7Mb after the conversion.  
> I was suspicious about that and when I tried it the performace was 
> a lot lower then I it used to be (actions that took 2s are now taking 8s).  

When you say "actions", are you refering to the execution of queries or to other 
database actions?  If you've noticed this problem with queries, are you able to 
tell if the extra time is spent during compilation or execution?  That is, if 
you prepare the query (using a prepared statement) and then execute it, is it 
possible for you to tell which part is taking longer now than it used to--the 
"prepare" or the "execute"?

The reason I ask is that there are some optimizer changes which are part of 
10.1.3 (DERBY-805, DERBY-1073, DERBY-1007) that could potentially lead to 
increased compilation (prepare) time for large queries.  But those changes 
should not be leading to an increase in query execution time--so if you're 
seeing the latter, then perhaps something is amiss.

Any chance you could post an example of the query(-ies) that have slowed down?


View raw message