Re: CHECKPOINT_WARNING GUC variable addition

Neil Conway wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > The following patch adds a GUC variable CHECKPOINT_WARNING which
> > generates a server log message if the checkpoint caused by WAL file
> > filling happens more frequently than (default) 30 seconds.
>
> + Checkpoints are fairly expensive because they force all dirty kernel
> + buffers to disk using the operating system <literal>sync()</> call.
> + Busy servers may fill checkpoint segment files too quickly,
> + causing excessive checkpointing. If such forced checkpoints happen
> + more than <varname>CHECKPOINT_WARNING</varname> seconds
>
> That should be: "happen more [frequently] than ..."

Great. New text:

+ Checkpoints are fairly expensive because they force all dirty kernel
+ buffers to disk using the operating system <literal>sync()</> call.
+ Busy servers may fill checkpoint segment files too quickly,
+ causing excessive checkpointing. If such forced checkpoints happen
+ more frequently than <varname>CHECKPOINT_WARNING</varname> seconds,
+ a message, will be output to the server logs recommending increasing
+ <varname>CHECKPOINT_SEGMENTS</varname>.

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