On Sun, May 3, 2009 at 3:13 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Mon, Apr 6, 2009 at 11:15 AM, Robert Haas <robertmh...@gmail.com> wrote: >> So based on this comment and Stephen's remarks, I'm going to assume >> that I'm succumbing to a fit of unjustified paranoia and re-implement >> as you suggest. > > OK, new version of patch, this time with the weird scaling removed and > the datatype changed to float4. >
In this paragraph i think you mean: "ALTER TABLE ... ALTER COLUMN ... SET DISTINCT"? <para> + The analyzer also estimates the number of distinct values that appear + in each column. Because only a subset of pages are scanned, this method + can sometimes be quite inaccurate, especially for large tables. If this + inaccuracy leads to bad query plans, the analyzer can be forced to use + a more correct value with <command>ALTER TABLE ... ALTER COLUMN ... SET + STATISTICS</command> (see <xref linkend="sql-altertable" + endterm="sql-altertable-title">). + </para> -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL AsesorÃa y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157 -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers