Re: SSI performance

On 04.02.2011 15:37, Robert Haas wrote:
> Not sure.  How much benefit do we get from upgrading tuple locks to
> page locks?  Should we just upgrade from tuple locks to full-relation
> locks?

Hmm, good question. Page-locks are the coarsest level for the b-tree 
locks, but maybe that would make sense for the heap.

> It also seems like there might be some benefit to caching the
> knowledge that we have a full-relation lock somewhere, so that once we
> get one we needn't keep checking that.  Not sure if that actually
> makes sense...

Well, if you reverse the order of the hash table lookups, that's 
effectively what you get.

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