Re: [HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-03 Thread Simon Riggs
On Thu, Nov 3, 2011 at 12:21 AM, Greg Smith g...@2ndquadrant.com wrote: With some trivial checkpoints containing a small amount of data skipped now, aren't there some cases where less WAL data will be written than before?  In that case, the user visible behavior here would be different.  I'd

Re: [HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-03 Thread Robert Haas
On Wed, Nov 2, 2011 at 8:21 PM, Greg Smith g...@2ndquadrant.com wrote: In cases where there are little or no writes to the WAL, checkpoints will be skipped even if checkpoint_timeout has passed.  At least one new WAL segment must have been created before an automatic checkpoint occurs.  The

[HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-02 Thread Robert Haas
On Wed, Nov 2, 2011 at 12:34 PM, Simon Riggs si...@2ndquadrant.com wrote: On Wed, Nov 2, 2011 at 4:15 PM, Robert Haas robertmh...@gmail.com wrote: On Wed, Nov 2, 2011 at 11:39 AM, Simon Riggs si...@2ndquadrant.com wrote: Reduce checkpoints and WAL traffic on low activity database server

Re: [HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-02 Thread Simon Riggs
On Wed, Nov 2, 2011 at 6:27 PM, Robert Haas robertmh...@gmail.com wrote: Again, it's no longer the maximum time between automatic checkpoints. You're missing the point that it never was like that. I've not altered the situation. And it doesn't matter either, so I will ignore. If you see a

Re: [HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-02 Thread Greg Smith
On 11/02/2011 05:48 PM, Simon Riggs wrote: On Wed, Nov 2, 2011 at 6:27 PM, Robert Haasrobertmh...@gmail.com wrote: Again, it's no longer the maximum time between automatic checkpoints. You're missing the point that it never was like that. I've not altered the situation.

Re: [HACKERS] Re: [COMMITTERS] pgsql: Reduce checkpoints and WAL traffic on low activity database serv

2011-11-02 Thread Tom Lane
Greg Smith g...@2ndquadrant.com writes: On 11/02/2011 05:48 PM, Simon Riggs wrote: You're missing the point that it never was like that. I've not altered the situation. Robert's point is more that the existing docs are already broken; this new patch can just increase how bad the drift