Re: pgsql 7.2.3 crash - Mailing list pgsql-hackers

From Joe Conway
Subject Re: pgsql 7.2.3 crash
Date
Msg-id 3DA90533.10900@joeconway.com
Whole thread Raw
In response to Re: pgsql 7.2.3 crash  (Laurette Cisneros <laurette@nextbus.com>)
Responses Re: pgsql 7.2.3 crash
List pgsql-hackers
Tom Lane wrote:
> Hackers: we might reasonably fix this by doing a deep copy of the
> relcache's trigger info during initResultRelInfo(); or we could fix it
> by getting rid of ri_TrigDesc and re-fetching from the relcache every
> time.  The former would imply that trigger state would remain unchanged
> throughout a query, the latter would try to track currently-committed
> trigger behavior.  Either way has got pitfalls I think.
> 
> The fact that there's a problem at all is because people are using
> direct poking of the system catalogs instead of some kind of ALTER TABLE
> command to disable/enable triggers; an ALTER command would presumably
> gain exclusive lock on the table and thereby delay until active queries
> finish.  But that technique is out there (even in pg_dump files :-() and
> so we'd best try to make the system proof against it.
> 
> Any thoughts on which way to go?

I'd say:

1. go with the former
2. we definitely should also have an ALTER command to allow disable/enable of   triggers
3. along with the ALTER, document that directly messing with the system   catalogs is highly discouraged

Joe




pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: Difference between 7.2 and 7.3, possible bug?
Next
From: Barry Lind
Date:
Subject: Re: Difference between 7.2 and 7.3, possible bug?