Re: Pg_upgrade speed for many tables

On Mon, Nov 5, 2012 at 1:14 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Mon, Nov 5, 2012 at 4:07 PM, Jeff Janes <jeff.janes@gmail.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.

Yeah, I was wondering what a fool-proof way of doing that would be,
without implementing a new feature.  Turning synchronous_commits back
on and then doing and committing a transaction guaranteed to generate
WAL would do it.

Would a simple 'select pg_switch_xlog();' always accomplish the desired flush?

Cheers,

Jeff