Re: Impact of checkpoint_segments under continual load conditions

On 7/19/05, PFC <lists@boutiquenumerique.com> wrote:
>
>         What happens if, say at iteration 6000 (a bit after the mess starts), you
> pause it for a few minutes and resume. Will it restart with a plateau like
> at the beginning of the test ? or not ?

Not sure... my benchmark is designed to represent what the database
will do under "typical" circumstances, and unfortunately these are
typical for the application.  However, I can see about adding some
delays, though multiple minutes would be absurd in the application.
Perhaps a 5-10 second day? Would that still be interesting?

>         What if, during this pause, you disconnect and reconnect, or restart the
> postmaster, or vacuum, or analyze ?

Well, I don't have the numbers any more, but restarting the postmaster
has no effect, other than the first few hundreds COPYs are worse than
anything (3-4x slower), but then it goes back to following the trend
line.  The data in the chart for v8.0.3 includes running pg_autovacuum
(5 minutes).

Chris
--
| Christopher Petrilli
| petrilli@gmail.com