> That explains it ...
>
> profiles_faith | count
> ----------------+--------
> 0 | 485938
> 1 | 2
> 2 | 6
> 7 | 2
> 8 | 21
> (5 rows)
>
> Cool, another waste of space *sigh*
>
> thanks ...
>
>
> On Wed, 13 Feb 2002, Tom Lane wrote:
>
> > "Marc G. Fournier" <scrappy@hub.org> writes:
> > > Okay, if I'm understanding pg_stats at all, which I may not be, n_distinct
> > > should represent # of distinct values in that row, no?
> > > But, I have one field that has 5 distinct values:
> > > But pg_stats is reporting 1:
> >
> > The pg_stats values are only, um, statistical. If 99.9% of the table is
> > the same value and the other four values appear only once or twice, it's
> > certainly possible for ANALYZE's sample to include only the common value
> > and miss the rare ones. AFAIK that will not break anything; if you have
> > an example where the planner seems to be fooled because of this, let's
> > see it.
Hmm ? How about select * from xxx where profiles_faith = 7
would estimate all rows, no ? Instead of 2.
That is why I think a bin for "very uncommon" values could also be
useful sometimes.
Andreas