db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Thiwanka Somasiri <asthiwa...@gmail.com>
Subject Add tools for improved analysis and understanding of query plans and execution statistics
Date Tue, 13 Apr 2010 16:52:28 GMT
Hi all,
               I read the Derby reference manual and Derby tuning materials
to some extent to get the scope for this project and got to know that all
the statistics that are logged into the logQueryPlan are stored in the
XPLAIN tables as well.One problem we had earlier was to find out all the
statistic data that can occur for a query.I studied the code for XPLAIN
tables to some extent and found that there are all the statistic variables
that are stored in the tables.So we can grab them from the source code.So it
will be very easy to get the values from the XPLAIN tables rather that
retrieving them from the derby.log file.

For example see the following package to understand the above desiption :

Now we do not have to worry about converting text file into XML.We can just
create a Java Object and feed it with the statistics from the XPLAIN
tables.Then we can convert it into XML using a third party tool.Hope your
comments in this regard.

Thank you.



A.S.Thiwanka Somasiri
Department of Computer Science and Engineering,
University of Moratuwa,
Sri Lanka.

Skype : executionerwild
MSN   : thiwas@ymail.com

View raw message