Hello
I work as the DBA in a startup, and we're running a mid-range
linux+PostgreSQL stack (1.1 TB database, ~75% of which is multimedia data).
This is our version() string.
PostgreSQL 9.2.11 on x86_64-unknown-linux-gnu, compiled by gcc (GCC)
4.4.7 20120313 (Red Hat 4.4.7-11), 64-bit
A couple days ago we made a beginners mistake and upgraded our minor
from 9.2.10 to 9.2.11 on the same night as an hardware swap over due to
HW issues (according to our supplier, the chassis is like by like the
same specs as the replaced one, and discs have been moved over).
Severe performance issues hit us since.
We've done all the profiling, our I/O is minimal as usual, cache hit
rates are just as high as usual, all query plans are the same, the
application hasn't changed at all and yet everything is unbearably slow.
We're fairly confident that it's an issue with the hardware but we have
political reasons to downgrade PG to 9.2.10 to show the hosting supplier
that it's their fault.
The release notes for 9.2.11 mention no data structure changes (in line
with the usual PG versioning policy). Is it just as safe to downgrade
too? We tested it on a couple non-critical boxes to no ill effect
whatsoever, but we'd like a second opinion before we do it on the live
installation too.
TIA and best regards
Fabio