Hello.
These days I was trying to temporarily disable triggers, too, and had much
problems with ALTER TABLE..DISABLE TRIGGER ALL. So, I was googling for another
solution and have found this: http://www.varlena.com/GeneralBits/101.php. Works
OK in my case...
Turn off triggers for bulk load Issue: 9-3
[GENERAL] Turning off triggers ? 25-Nov-2002
Another issue with bulk loading is triggers firing with each row inserted. If
you are sure your data is trustworthy and already meets your referential
integrity requirements, you can turn off triggers for the bulk load and turn
them back on immediately afterward. You should not use this option when your
data is not completely clean.
The reltriggers field in the pg_class table contains the number of triggers
active for each table. It can be set to 0 the disable the triggers, but will
need to be reset to the proper number of triggers to have them re-enabled.
UPDATE "pg_class" SET "reltriggers" = 0 WHERE "relname" = 'tablename';
UPDATE pg_class SET reltriggers = (
SELECT count(*) FROM pg_trigger where pg_class.oid = tgrelid)
WHERE relname = 'table name';
Contributors: Stephan Szabo sszabo at megazone23.bigpanda.com, Jean-Luc
Lachance jllachan at nsd.ca, Glen Eustace geustace at godzone.net.nz, Adam
Witney awitney at sghms.ac.uk
Regards,
Zlatko
----- Original Message -----
From: Dmitry Koterov
To: Postgres General
Sent: Friday, July 06, 2007 10:06 PM
Subject: [GENERAL] Update a single row without firing its triggers?
Hello.
Suppose I have a table tbl with columns (a, b, c, counter).
And I have 5 ON UPDATE triggers assigned to this table. They process (a, b,
c) columns, but never depend on counter.
I need to update counter field, but I know that it is totally independent, so
- for performance reason I want to temporarily disable all triggers during the
tbl.counter updation.
How could I do it?
(Please do not offer ALTER TABLE tbl DISABLE TRIGGER ALL. It is NOT a
production case: ALTER TABLE locks all the table during, so it cannot be used
in heavy-loaded systems.)
(Please do not also offer top move the counter to another table, because it
is used in complex indices, e.g. INDEX ON (counter, a, c) to speedup fetching.)
Possible solution: add an additional column named "disable_trg" BOOLEAN: (a,
b, c, disable_trg). Then, I use the following UPDATE:
UPDATE tbl SET counter = counter + 1, disable_trg = true WHERE a = 10;
In each trigger I firstly run an instruction:
IF NEW.disable_trg THEN RETURN NEW; END IF;
And the latest trigger resets disable_trg field to NULL, so it is not written
to the table. So, in some queries I may explicitly specify do I need to disable
triggers or not.
But this solution (the only possible?) looks like a brute-force method.
Possibly Postgrs has another one, better?
