To see the effect of this in a different environment I started a similar
test running with IBM 1.5 VM on Linux. Unfortunately, the machine I
decided to use was a shared server so during part of the test run some
other testing have been running in parallel. I plan to try to re-run
these tomorrow.
But anyway, I am attaching the graph even if it is not correct. It seems
that the negative effect of this patch is much less when running on the
IBM VM/Linux (the last part of the second curve I expect was run in
parallel with some other testing). So if anyone is looking into this and
using a different VM (or OS) than I did they might not see the large
drop I see in my tests.
Olav
Mike Matrigali wrote:
Are these tests checked in so that I can run them in my environment?
Olav Sandstaa wrote:
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
------------------------------------------------------------------------
