Re: Redesigning checkpoint_segments

On Thu, Feb 5, 2015 at 2:11 PM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:
> Except that, when setting up servers for customers, one thing I pretty
> much always do for them is temporarily increase checkpoint_segments for
> the initial data load. So having Postgres do this automatically would
> be a feature, not a bug.

Right!

> I say we go with ~~ 1GB. That's an 8X increase over current default
> size for the maximum

Sounds great.

> Default of 4 for min_wal_size?

I assume you mean 4 segments; why not 3 as currently? As long as the
system has the latitude to ratchet it up when needed, there seems to
be little advantage to raising the minimum. Of course I guess there
must be some advantage or Heikki wouldn't have made it configurable,
but I'd err on the side of keeping this one small. Hopefully the
system that automatically adjusts this is really smart, and a large
min_wal_size is superfluous for most people.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company