Re: postmaster 8.2 eternally hangs in sempaphore lock acquiring

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
> Ok, I think I know what's happening. In btbulkdelete we have a 
> PG_TRY-CATCH block. In the try-block, we call _bt_start_vacuum which 
> acquires and releases the BtreeVacuumLock. Under certain error 
> conditions, _bt_start_vacuum calls elog(ERROR) while holding the 
> BtreeVacuumLock. The PG_CATCH block calls _bt_end_vacuum which also 
> tries to acquire BtreeVacuumLock.

This is definitely a bug (I unfortunately didn't see your message until
after I'd replicated your reasoning...) but the word from Shuttleworth
is that he doesn't see either of those messages in his postmaster log.
So it seems we need another theory.  I haven't a clue at the moment though.

			regards, tom lane