Re: Triggers

jfk@sigsys.com wrote in article <33248156.168F@sigsys.com>... > Hello all, > > I was wondering about a trigger performance issue that we are > coming across currently. > > I am in the process of converting our Oracle database to Informix 7.1 > and I am noticing quite a few things that concern me. I hope someone > can help clarify a few things for me. > > Since I'm no longer to declare variables in triggers, I have to > create a stored procedure to do my log table inserts (I need a few > other fields in the log table that I add during the insert). Is this > going to create a major I/O bottleneck for us? We have about 30 users > at a time using the system. I have implemented several systems that use stored procedures to populate "audit trail" or "log" tables and I would rate the performance (an extremely subjective) "good". OLTP users will typically notice no difference when the trigger is in place from when it is not. Batch processes which update LOTS of records will run noticably slower (but not unacceptably so) with the triggers in place, but this is to be expected. Something that can help a great deal -- put your "log" table(s) in a different dbspace (on a different physical disk, of course) than the table(s) being audited. > > I was also wondering if there was a way to keep a global database > variable. I read about the DEFINE GLOBAL statement, but I am not sure > how the database locks that variable if multiple users are trying to > update/access it. I too have READ about stored procedure GLOBAL variables, but I'm not sure about multi-user locking behavior. -- Irwin Goldstein Objective Software Systems, Inc. http://www.objectsoft.com