Re: pre-commit triggers

Attached is a patch to provide a new event trigger that will fire on transaction commit. I have tried to make certain that it fires at a sufficiently early stage in the commit process that some of the evils mentioned in previous discussions on this topic aren't relevant.

The triggers don't fire if there is no real XID, so only actual data changes should cause the trigger to fire.

I have not looked at the patch, but does it also run pre-rollback ?

If not, how hard would it be to make it so ?

They also don't fire in single user mode, so that if you do something stupid like create a trigger that unconditionally raises an error you have a way to recover.

This is intended to be somewhat similar to the same feature in the Firebird database, and the initial demand came from a client migrating from that system to Postgres.

cheers

andrew

-- 
Hannu Krosing
PostgreSQL Consultant
Performance, Scalability and High Availability
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