On Wednesday, February 15, 2012 10:38:23 AM Venkat Balaji wrote: > On Wed, Feb 15, 2012 at 12:21 PM, Scott Marlowe <scott.marl...@gmail.com>wrote: > > On Tue, Feb 14, 2012 at 10:57 PM, Venkat Balaji <venkat.bal...@verse.in> > > > all of these 1000 files get filled up in less than 5 mins, there are > > > chances that system will slow down due to high IO and CPU. > > As far as I know there is no data loss issue with a lot of checkpoint > > segments. > Data loss would be an issue when there is a server crash or pg_xlog crash > etc. That many number of pg_xlog files (1000) would contribute to huge data > loss (data changes not synced to the base are not guaranteed). Of-course, > this is not related to the current situation. Normally we calculate the > checkpoint completion time, IO pressure, CPU load and the threat to the > data loss when we configure checkpoint_segments. I think you might be misunderstanding something. A high number of checkpoint_segments can lead to slower recovery - all those changes need to be reapplied - but it won't lead to lost data. The data inside the wal will be fsynced at appropriate times (commit; background writer; too much written).
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