Re: Avoiding adjacent checkpoint records - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: Avoiding adjacent checkpoint records
Date
Msg-id 4FD1E10802000025000481F5@gw.wicourts.gov
Whole thread Raw
In response to Re: Avoiding adjacent checkpoint records  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Avoiding adjacent checkpoint records  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <robertmhaas@gmail.com> wrote:
> if the database has checkpointed
I haven't been exactly clear on the risks about which Tom and Robert
have been concerned; is it a question about whether we change the
meaning of these settings to something more complicated?:
checkpoint_segments (integer)   Maximum number of log file segments between automatic WAL   checkpoints
checkpoint_timeout (integer)   Maximum time between automatic WAL checkpoints
I can see possibly changing the latter when absolutely nothing has
been written to WAL since the last checkpoint, although I'm not sure
that should suppress flushing dirty pages (e.g., from hinting) to
disk.  Such a change seems like it would be of pretty minimal
benefit, though, and not something for which it is worth taking on
any risk at all.  Any other change to the semantics of these
settings seems ill advised on the face of it.
... or am I not grasping the issue properly?
-Kevin


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