Re: "slow" queries

On Mon, Mar 2, 2009 at 2:24 PM, Tim Bunce <Tim.Bunce@pobox.com> wrote:
> On Mon, Mar 02, 2009 at 02:29:31PM -0500, Tom Lane wrote:
>> Brian Cox <brian.cox@ca.com> writes:
>> > select locktype,database,relation,virtualxid,virtualtransaction,pid,mode
>> > from pg_locks order by mode;
>>
>> If you hadn't left out the "granted" column we could be more sure,
>> but what it looks like to me is the DROP (pid 13842) is stuck behind
>> the <IDLE> transaction (pid 13833).  In particular these two rows of
>> pg_locks look like a possible conflict:
>>
>> >   relation      | 26472437 | 26472508 |            | 15/69749
>> > | 13842 | AccessExclusiveLock
>>
>> >   relation      | 26472437 | 26472508 |            | 11/131
>> > | 13833 | AccessShareLock
>
> Would it be possible to write a stored procedure that would read
> pg_locks, and other relevant tables, and list what's blocking what
> in a simplified form?

I'm sure a query could use just connect by from tablefuncs, or WITH
under 8.4 and get it.