DB2 update is very slow

A simple SQL, update A set A.a =? Where A.b =?; single business soon, about 0.03 seconds, but when running pressure test execution efficiency is particularly slow, about 2 seconds, and for you to help think about what might be the cause., In addition, according to this table query very much, will not be a lock for the table? When running pressure do monitoring of the background, the lock is there, but soon released, will not be not to monitor? And the select will have an impact on the update? Seeking advice!

Started by Webb at December 13, 2016 - 2:29 PM

Push yourself, don't sink....

Posted by Webb at December 25, 2016 - 3:00 PM

1.A.b has no index
2 query can reduce the transaction isolation level, avoid to acquire the lock

Posted by Lynn at January 05, 2017 - 3:05 PM

By default, the select statement also need to lock, lock waiting may be complicated by severe. Consider isolation level reduced query to UR and then run performance test.

Posted by Lynn at January 13, 2017 - 4:13 PM

Recommended for all queries are with ur which can avoid the lock table!

Posted by Tommy at January 14, 2017 - 3:35 PM