On Thu, Sep 26, 2013 at 07:43:15AM -0400, Bruce Momjian wrote: > On Wed, Sep 25, 2013 at 08:48:11PM -0700, Peter Geoghegan wrote: > > On Wed, Sep 25, 2013 at 8:19 PM, Bruce Momjian <br...@momjian.us> wrote: > > > This thread had a lot of discussion about bloating. I wonder, does the > > > code check to see if there is a matching row _before_ adding any data? > > > > That's pretty much what the patch does. > > So, I guess my question is if we are only bloating on a contended > operation, do we expect that to happen so much that bloat is a problem? > > I think the big objection to the patch is the additional code complexity > and the potential to slow down other sessions. If it is only bloating > on a contended operation, are these two downsides worth avoiding the > bloat?
Also, this isn't like the case where we are incrementing sequences --- I am unclear what workload is going to cause a lot of contention. If two sessions try to insert the same key, there will be bloat, but later upsert operations will already see the insert and not cause any bloat. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
