Re: vacuum deadlock

Hi Yeb,

Thanks for your reply.
As far as I know, pg_class_oid_index and pg_class are postgresql internal
relations.

Normally, there is not application that directly using those relations.
How should I map this lock issue on this relations to my application side?
On which cases those are locked and used by applications?

Thanks

On Fri, Feb 5, 2010 at 2:36 PM, Yeb Havinga <yebhavinga(at)gmail(dot)com> wrote:

> Ibrahim Harrani wrote:
>
>> Hi,
>>
>> I am using PostgreSQL 8.3.7.
>> autovacuum is enabled in postgresql.conf
>>
>> I got a deadlock while vacuuming all databases with vacuumdb command.
>>
>> vacuumdb: vacuuming of database "mydb" failed: ERROR: deadlock detected
>> DETAIL: Process 1294 waits for AccessExclusiveLock on relation 2662 of
>> database ; blocked by process 1807.
>> Process 1807 waits for AccessShareLock on relation 1259 of database 16389;
>> blocked by process 1294.
>>
>> I think, because of this lock, deleting a large table (15 million records)
>> was taking too much time
>> How can I know the name of the relations 2662 and 1259?
>>
> postgres=# select oid,relname from pg_class where oid in (2662,1259);
> oid | relname ------+--------------------
> 2662 | pg_class_oid_index
> 1259 | pg_class
> (2 rows)
>
> Do you have any ide about the problem and solution?
>>
> It would be interesting to know what are the processes 1807 and 1294. Once
> that is known, try to avoid executing both processes concurrently.
>
> regards
> Yeb Havinga
>
>