Sergey Konoplev <gray(dot)ru(at)gmail(dot)com> writes:
> The table filled with about 7.5E+6 rows. Most of them have different
> from default values in obj_tsvector column. I use "estimated rows
> count trick" to make search results counter faster, and every time
> when obj_tsvector is used estimation rows count is extremely differ
> from actual (eg. 6821 vs 372012). I played with SET STATISTICS but
> have no success.
8.3 has just a stub estimator for @@. You might have better results
with 8.4. In the particular example you're showing, though, I don't
think the poor rowcount estimate is making any difference to the
plan choice.
regards, tom lane