On 3/29/13 9:30 AM, Mike Matrigali wrote:
On 3/29/2013 5:28 AM, Bergquist, Brett wrote:
Mike I have a reproducible case but the database is 132GB so it is
not practical. I am willing to dig in and try to help debug this.
On the issue that was pointed to, Mamta seemed to have used a debug
procedure that would print out more information on why the optimizer
is choosing what it does. This might be useful in this case as well.
So if someone can point me in the right area of the code to start
looking and adding some debug that would be helpful. I have done
some fixes for Derby in the past so I am able to build and debug Derby.
That's great. I am out of my depth debugging optimizer problems,
hopefully rick and/or mamta can help with that tool they were working
on. I think rick did some work to make it easier to turn on/off using
optional tools.
The simpler api to optimizer tracing is part of the 10.10.1 release
candidate which we're testing now. Instructions on how to use it can be
found in my 2013-03-14 comment on
https://issues.apache.org/jira/browse/DERBY-6022
Hope this helps,
-Rick
