Re: Limiting setting of hint bits by read-only queries; vacuum_delay

On 25 March 2013 14:26, Merlin Moncure <mmoncure@gmail.com> wrote:

> This is pretty similar to the proposal Atri and I just recently made.
> I am 100% in agreement that something must be done here...SELECT has
> none of the i/o mitigation features that vacuum has.  Is your idea
> better? probably (although you have to give a small penalty for a user
> facing tunable)

I was hoping this was a new idea entirely, since I was focusing on
simply limiting foreground work rather than trying to work out how to
optimise foreground work or work out how to make background tasks work
better.

> but we need testing against real world workloads, or
> at least a much better synthetic one than pgbench, which per recent
> discussions is probably the top objective of the project (a
> performance farm, etc.).

Self-tuning the background workloads needs lots of testing. Limiting
foreground work needs very little, or none.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services