Re: SIREAD lock versus ACCESS EXCLUSIVE lock

On 27.04.2011 22:59, Kevin Grittner wrote:
> For correct serializable behavior in the face of concurrent DDL
> execution, I think that a request for a heavyweight ACCESS EXCLUSIVE
> lock might need to block until all SIREAD locks on the relation have
> been released.  Picture, for example, what might happen if one
> transaction acquires some predicate locks, then commits (releasing
> its heavyweight lock on the table), and before concurrent READ WRITE
> transactions complete there is a CLUSTER on the table. Or a DROP
> INDEX.  :-(

Hmm, could we upgrade all predicate locks to relation-level predicate 
locks instead?

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