Re: Load Distributed Checkpoints, final patch

Heikki Linnakangas wrote:
> For comparison, imola-328 has full_page_writes=off. Checkpoints last ~9
> minutes there, and the graphs look very smooth. That suggests that
> spreading the writes over a longer time wouldn't make a difference, but
> smoothing the rush at the beginning of checkpoint might. I'm going to
> try the algorithm I posted, that uses the WAL consumption rate from
> previous checkpoint interval in the calculations.

One thing that concerns me is that checkpoint smoothing happening just
after the checkpoint is causing I/O at the same time that
full_page_writes is causing additional I/O.  Ideally we would do the
smoothing toward the end of the checkpoint cycle, but I realize that has
problems of its own.

--
  Bruce Momjian  <bruce@momjian.us>          http://momjian.us
  EnterpriseDB                               http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +