Re: Pg_upgrade speed for many tables

On Mon, Nov 5, 2012 at 04:14:47PM -0500, Robert Haas wrote:
> On Mon, Nov 5, 2012 at 4:07 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
> > Or have options for pg_dump and pg_restore to insert "set
> > synchronous_commit=off" into the SQL stream?
>
> It would be kind of neat if we had a command that would force all
> previously-asynchronous commits to complete. It seems likely that
> very, very few people would care about intermediate pg_dump states, so
> we could do the whole dump asynchronously and then do "FORCE ALL
> COMMITS;" or whatever at the end.

Actually, I had assumed that a session disconnection forced a WAL fsync
flush, but now I doubt that. Seems only server shutdown does that, or a
checkpoint. Would this work?

SET synchronous_commit=on;
CREATE TABLE dummy(x int);
DROP TABLE dummy;

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +