Re: SIREAD lock versus ACCESS EXCLUSIVE lock

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-hackers@postgresql.org, "<Simon Riggs" <simon@2ndquadrant.com>, Dan Ports <drkp@csail.mit.edu>
Date: 2011-06-03T18:45:56Z
Lists: pgsql-hackers
On 03.06.2011 21:04, Kevin Grittner wrote:
> Also, if anyone has comments or hints about the placement of those
> calls, I'd be happy to receive them.

heap_drop_with_catalog() schedules the relation for deletion at the end 
of transaction, but it's still possible that the transaction aborts and 
the heap doesn't get dropped after all. If you put the 
DropAllPredicateLocksFromTable() call there, and the transaction later 
aborts, you've lost all the locks already.

I think you'll need to just memorize the lock deletion command in a 
backend-local list, and perform the deletion in a post-commit function. 
Something similar to the PendingRelDelete stuff in storage.c. In fact, 
hooking into smgrDoPendingDeletes would work, but that seems like a 
modularity violation.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com