For those interested in the I/O results (as reported by iostat) of
moving where the stats files are written (using the method I
described in http://archives.postgresql.org/pgsql-general/2007-12/
msg00106.php) on our production system: service time has dropped from
an average of 95.76ms to about 8ms, Mb/s written has dropped from an
average of 47 to 4, number of active transactions from between 80 and
100 to below 10, percent wait from 40 to 10. If anybody wants exact
numbers (or, just nicely formatted) I can do that, but it'll take
twiddling the labels on our cacti graphs and, since I have the
visual, I haven't needed to do that yet.
Now, as I explained before, we're working with approximately 400GB of
data (and growing) and we have a "unique" schema in that it has more
relations that I'd like to have to be working with, so other ymmv,
but I'd call those numbers pretty impressive.
Erik Jones
Software Developer | Emma®
erik@myemma.com
800.595.4401 or 615.292.5888
615.292.0777 (fax)
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