Robert Haas wrote:
> Back to the idea at hand - I proposed something a bit along these
> lines upthread, but my idea was to proactively perform the fsyncs on
> the relations that had gone the longest without a write, rather than
> the ones with the most dirty data. I'm not sure which is better.
> Obviously, doing the ones that have "gone idle" gives the OS more time
> to write out the data, but OTOH it might not succeed in purging much
> dirty data. Doing the ones with the most dirty data will definitely
> reduce the size of the final checkpoint, but might also cause a
> latency spike if it's triggered immediately after heavy write activity
> on that file.
Crazy idea #2 --- it would be interesting if you issued an fsync
_before_ you wrote out data to a file that needed an fsync.
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com
+ It's impossible for everything to be true. +