Our database with version 7.2.9 running on AIX has a serious problem.
I always restore a new database on the same server and do my experiments in that database. Since the records have reasonably increased, I did need of using Explain-SQL tool.
According to the results; I create useful indexes on various tables.The output works well.We can obtain really good performances and I immediately apply the studies on our real database.
Where is the problem?The problem lies when I do REORG operation,the timeron values of EXPLAIN-SQL gives me terrifying results such as >20.000!;although it was just residing in <250 timerons level for even most complex queries.
One clue is,my indexes are NEVER used in EXPLAIN_SQL graph anymore.
When I look at the indexes with REORGCHK,I see that my indexes are normalized.There seems no abnormal event.
I tried dropping and recreating the indexes but couldn't get result from that.
What must I do?Why does REORG demolishes my beautiful way of reading my queries?There must be something I am missing.But what?One last question is when should I reorganize my tables (without getting any performance damage of course)?
If anyone can help me on these subjects-- even slightest I'd be very pleased.
Thanks for now.
Salih Sipahi
Software Engineer.
City of Istanbul Turkey
s.sipahi@sahinlerholding.com.tr
I always restore a new database on the same server and do my experiments in that database. Since the records have reasonably increased, I did need of using Explain-SQL tool.
According to the results; I create useful indexes on various tables.The output works well.We can obtain really good performances and I immediately apply the studies on our real database.
Where is the problem?The problem lies when I do REORG operation,the timeron values of EXPLAIN-SQL gives me terrifying results such as >20.000!;although it was just residing in <250 timerons level for even most complex queries.
One clue is,my indexes are NEVER used in EXPLAIN_SQL graph anymore.
When I look at the indexes with REORGCHK,I see that my indexes are normalized.There seems no abnormal event.
I tried dropping and recreating the indexes but couldn't get result from that.
What must I do?Why does REORG demolishes my beautiful way of reading my queries?There must be something I am missing.But what?One last question is when should I reorganize my tables (without getting any performance damage of course)?
If anyone can help me on these subjects-- even slightest I'd be very pleased.
Thanks for now.
Salih Sipahi
Software Engineer.
City of Istanbul Turkey
s.sipahi@sahinlerholding.com.tr