Re: Slow execution time when querying view with WHERE clause - Mailing list pgsql-performance

From Mike Mascari
Subject Re: Slow execution time when querying view with WHERE clause
Date
Msg-id 41A51061.30805@mascari.com
Whole thread Raw
In response to Re: Slow execution time when querying view with WHERE clause  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Tom Lane wrote:
> Um ... doh ... analyze.c about line 1550:
>
>     /* We can only compute valid stats if we found some non-null values. */
>     if (nonnull_cnt > 0)
>        ...
>
> There's a bit of an epistemological issue here: if we didn't actually
> find any nonnull values in our sample, is it legitimate to assume that
> the column is entirely null?  On the other hand, if we find only "3" in
> our sample we will happily assume the column contains only "3", so I
> dunno why we are discriminating against null.  This seems like a case
> that just hasn't come up before.

Will this discriminatory policy toward null end for 8.0?

Mike Mascari



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