On Wed, Jun 06, 2012 at 03:08:05PM -0400, Robert Haas wrote: > On Mon, Jun 4, 2012 at 9:26 PM, Jeff Davis <pg...@j-davis.com> wrote: > > Thoughts? > > Simon already proposed a way of doing this that doesn't require > explicit user action, which seems preferable to a method that does > require explicit user action, even though it's a little harder to > implement. His idea was to store the XID of the process creating the > table in the pg_class row, which I think is *probably* better than > your idea of having a process that waits and then flips the flag. > There are some finicky details though - see previous thread for > discussion of some of the issues.
I think both improvements have a place. Loads to a new heap should take as many automatic shortcuts as practical. Loads to an existing heap also matter, and Jeff's proposal helps those. > It would be very nice to have a method that detects whether or not > there is only one open snapshot in a particular backend. Any time > that condition is met, tuples written into a table created or > truncated in the current transaction can be written with > HEAP_XMIN_COMMITTED already set. Perhaps criteria like those in CheckTableNotInUse() would suffice? -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
