I believe I have found a bug in the vacuum procedures. I am helping out
a friend who is running a "alumni" sites of sorts using postgresql 7.2.3
as the backend. The first page someone loads does most of the queries
that any page will need and stores it in a session file (php style) and
hands a cookie to the user.
If I never do a vacuum analyze, it takes between 8-11 (high spikes
around 23) seconds most of the time for this first page to load. If I
do vacuum, nothing seems to change. If I do a vacuum analyze, the
minimum load time is between 41-44 seconds. Higher system loads,
instead of adding 4-10 seconds, easily double the number up beyond 80
seconds. Yes, each of these tables have at least one index (the most
indexes I believe are 4). Those with multiple, I believe, all have a
primary index key.
Effects of vacuum full and vacuum freeze haven't been tested. The only
way to recover from these horrible times seems dump/drop/reload.
Is this a bug, known or otherwise, are their workarounds besides don't
do it?
Thank you,
Trever Adams
P.S. This is a RedHat 8.0 box with all errata fixes. Specifics can be
provided later if needed.
--
"Perilous to all of us are the devices of an art deeper than we possess
ourselves." -- Gandalf the White [J.R.R. Tolkien, "The Two Towers", Bk
3, Ch. XI]