Re: Blocks read for index scans

Jim Nasby <jnasby@pervasive.com> writes:
> While working on determining a good stripe size for a database, I
> realized it would be handy to know what the average request size is.
> Getting this info is a simple matter of joining pg_stat_all_tables
> and pg_statio_all_tables and doing some math, but there's one issue
> I've found; it appears that there's no information on how many heap
> blocks were read in by an index scan. Is there any way to get that info?

If the table is otherwise idle, the change in the table's entry in
pgstatio_all_tables should do, no?

(This is as of 8.1 ... older versions acted a bit differently IIRC.)

            regards, tom lane