Re: CIC and deadlocks

On Sat, 2007-03-31 at 17:45 +0530, Pavan Deolasee wrote:
> 
> Isn't CREATE INDEX CONCURRENTLY prone deadlock conditions ?
> I saw one with VACUUM today. But I think it can happen with other
> commands like VACUUM FULL, CLUSTER, CREATE INDEX
> CONCURRENTLY and so on. These commands conflict on the 
> ShareUpdateExclusiveLock held by CIC and hence would wait for
> CIC to release the lock. At the same time, CIC would wait for these
> transactions to complete.
> 
> We know that these commands are run in a separate transaction 
> and do not do any index fetches or inserts/updates. So in principle
> CIC need not wait for these transactions to complete in any
> of its waits. May be we can skip waits on the transactions that
> are running one of these commands. 

Yes, because I proposed it already. :-)

"utility transactions" in - Latest plans for Utilities with HOT

--  Simon Riggs              EnterpriseDB   http://www.enterprisedb.com