db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Olav Sandstaa <Olav.Sands...@Sun.COM>
Subject Performance regression after check-in on DERBY 2537 (SVN 531971)
Date Thu, 26 Apr 2007 13:00:12 GMT
The two last days I have seen a performance regression in some of the 
performance tests I run. For some of the tests the reduction in 
throughput is about 15 percent. It seems like the regression is 
introduced by the latest check-in on DERBY-2537, svn 531971.

I have attached a graph showing the throughput I get when running 
single-record select operation on a table. The queries use a secondary 
index for finding the record to select. The test has been run with 1 to 
20 concurrent client against embedded Derby. I have run the test with 
and without SVN 531971. As the graph shows, the performance reduction is 
between 12 and 15 percent for all runs.

The schema looks like this:

  CREATE TABLE  t1 id INTEGER sec_id INTEGER data CHARACTER(100) PRIMARY 
KEY(id))
  CREATE INDEX nonprimary_index ON t1 (sec_id)

Each query do the select on the secondary index and retrieves the data 
field (a CHARACTER(100) field).

I would expect some of the changes done in the patch to have some 
influence on the performance, but not in the order of 10-15 percent.

The tests are run on a 2 CPU Opteron server running Solaris 10 and JDK 6.

Olav






Mime
View raw message