In article <758d5e7f05070808305c049aae@mail.gmail.com>,
Dawid Kuroczko <qnex42@gmail.com> writes:
> Use
> EXPLAIN SELECT * FROM yourcountedtable;
> Planner seems to track estimated statistics on-the-fly. :)
> You can even wrap EXPLAIN SELECT in a pgsql function if you
> need it.
Do you know how to do that? A function "approx_count(tablename)"
would be really handy, but
FOR row IN EXECUTE 'EXPLAIN SELECT * FROM ' || tbl LOOP
fails with the following message:
ERROR: cannot open non-SELECT query as cursor
> PS: And be aware that these are 'statistics'. And the statement that there
> are lies, big lies and statistics is sometimes true even for PostgreSQL. ;-)
Does this mean that PostgreSQL believes only in statistics it has
faked itself? ;-)