Re: Deadlocks in 7.4.x ...

"Marc G. Fournier" <scrappy@postgresql.org> writes:
> ...
>    3) All deadlocks are fighting for the same relation: 4335271, which is
>       the tsearch2 fulltext index on the articles table:
>       articles_idxft1_idx.

> DETAIL:  Process 8122 waits for AccessExclusiveLock on relation 4335271 of database 17142; blocked by process 11846.
> Process 11846 waits for ShareLock on transaction 2897133915; blocked by process 10042.
> Process 10042 waits for AccessExclusiveLock on relation 4335271 of database 17142; blocked by process 8122.
> ----------------------------------
> DETAIL:  Process 10042 waits for AccessExclusiveLock on relation 4335271 of database 17142; blocked by process
11846.
> Process 11846 waits for ShareLock on transaction 2897133915; blocked by process 10042.

Gist indexes require AccessExclusiveLock for any update, so the blocks
on 4335271 just indicate an index update attempt.  The "ShareLock on
transaction" lines suggest a block on a row that is updated or selected
FOR UPDATE.  It's hard to say more without more info.  Do you have any
related foreign keys, for instance?
        regards, tom lane