Re: Issues with Triggers in an Oracle RAC

I doubt that. We used many triggers in one of our applications deployed in RAC without much issues.

We also had 11i apps on RAC without any such issue, with many custom triggers.

If they encounter any issues with triggers, I think, that should be considered as a bug and dealt that way. Of course, create a table, row level trigger insert million rows in single instance and then, repeat the same in RAC, with sql trace on. That should be a good test to prove that triggers shouldn't cause much issues. You would see other RAC related events if you concurrently insert from multiple nodes to a table, but I doubt library cache lock/pins to be an issue.

[of course, if the trigger has dynamic DDL statements, then that could cause issues, but we are not considering those kind of triggers ]

Thanks
Riyaj Shamsudeen
Senior DBA
www.pythian.com

On Wed, Apr 9, 2008 at 7:37 AM, Rumpi Gravenstein <rgravens_at_gmail.com> wrote:

> All,
>
> I've been having a conversation where I work about using triggers in our
> application environment. The DBAs here say that triggers are not
> appropriate in an Oracle RAC. Specifically they tell me:
>
> <snip>
> Triggers in a RAC environment have been known to cause library cache lock
> waits (in RAC because of the global cache and global coordination that
> occurs, this wait event gets more pronounced - lib cache concurrency). This
> was one of the main reasons we didn't do fast refreshes of snapshots for the
> heavily used tables. Currently we also have limited auditing turned on and
> it is trigger based and wouldn't want to open the flood-gates for trigger
> based solutions - primarily for performance reasons
> </snip>
>
> Needless to say I'm confused as I've used simple audit triggers to
> populate change user IDs and timestamps in rows for years without issue. I
> understand that if there is complicated trigger logic there may be problems,
> but for calculating audit columns I can't see it being an issue. Anyone
> else have a policy that doesn't allow triggers in RAC environments?
>
> We are on Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 -
> Prod.
>
> --
> Rumpi Gravenstein
>

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