Re: rapid degradation after postmaster restart

Joe Conway <mail(at)joeconway(dot)com> writes:
> The problem is this: the application runs an insert, that fires off a
> trigger, that cascades into a fairly complex series of functions, that
> do a bunch of calculations, inserts, updates, and deletes. Immediately
> after a postmaster restart, the first insert or two take about 1.5
> minutes (undoubtedly this could be improved, but it isn't the main
> issue). However by the second or third insert, the time increases to 7 -
> 9 minutes. Restarting the postmaster causes the cycle to repeat, i.e.
> the first one or two inserts are back to the 1.5 minute range.

I realize this question might take some patience to answer, but what
does the performance curve look like beyond three trials? Does it level
off or continue to get worse? If it doesn't level off, does the
degradation seem linear in the number of trials, or worse than linear?

I have no ideas in mind, just trying to gather data ...

regards, tom lane