Re: pg_locks "at-a-glance" view

On Wed, Jun 18, 2008 at 05:39:59PM -0700, Jeff Davis wrote:
> I was trying to create a more "at-a-glance" view of the pg_locks table.
> I included the SQL I came up with (after talking to Merlin) at the
> bottom of this message.
>
> The idea is to show any queries that are waiting on a lock, and the
> query that currently holds the lock on which those queries are waiting.
>
> Is my logic correct?

I'm not exactly sure, but it appears to match, at first blush, what's
in src/backend/storage/lmgr/lock.c:
    static const LOCKMASK LockConflicts[] = {

> Does anyone have any suggestions?

The function could be in SQL, with one minor bit in PL/PgSQL.  File
attached.

> I couldn't find a generally accepted way to do this, although I'm sure
> someone must have done something like this before.

There's stuff in the aforementioned lock.c, but I don't see anything
visible to SQL.

Cheers,
David.
--
David Fetter <david@fetter.org> http://fetter.org/
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