Re: FreeBSD upgrade causes performance degredation

"Peter Schmidt" <peterjs(at)home(dot)com> writes:
> Old function was something like this:
> SELECT COL1 FROM TABLE WHERE COL2 = SP_FUNCTION(ARG, ARG, ARG, ...)

> The query was modified so that the call to the second function was executed
> as a subselect (and thereby executed only once for all rows in the first
> select?):

> SELECT COL1 FROM TABLE WHERE COL2 = (SELECT SP_FUNCTION(ARG, ARG,
> ARG...))

This seems like a rather klugy substitute for marking the function
"iscachable". You might want to read up on that in the CREATE FUNCTION
documentation.

I don't see why an OS change would affect this though; I think you still
have more digging to do to understand the issue. Did you reinstall
Postgres after the OS update, and if so is it possible you neglected to
do VACUUM ANALYZE after reloading the database?

regards, tom lane