Re: "Bug" in statistics for v7.2? - Mailing list pgsql-hackers

From Marc G. Fournier
Subject Re: "Bug" in statistics for v7.2?
Date
Msg-id 20020213121458.H19107-100000@mail1.hub.org
Whole thread Raw
In response to "Bug" in statistics for v7.2?  ("Marc G. Fournier" <scrappy@hub.org>)
List pgsql-hackers
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.
>
>             regards, tom lane
>



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