On 2021-Oct-19, Michael Paquier wrote:
> On Mon, Oct 18, 2021 at 05:15:59PM -0300, Euler Taveira wrote:
> > I agree that it might surprise an user and it would be good to document it.
> > However, it does not belong to the description. I would add it to the Notes
> > section at the end of the ALTER TABLE page.
>
> No objections to the suggested addition and the location of the
> addition (paragraph of SET DATA TYPE rather than "Notes"), but I think
> that the phrasing could be better:
> "The column's statistics are removed, hence a follow-up ANALYZE is
> suited to update the statistics to the new column type."
Dunno, putting it in the middle of the existing paragraph looks odd to
me. I would put it in a separate one instead, as in the attached.
--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
diff --git a/doc/src/sgml/ref/alter_table.sgml b/doc/src/sgml/ref/alter_table.sgml
index 81291577f8..86fc15c8b3 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -198,6 +198,12 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
clause must be provided if there is no implicit or assignment
cast from old to new type.
</para>
+
+ <para>
+ When this form is used, the column's statistics are removed,
+ so running <command>ANALYZE</command> on the table afterwards
+ is recommended.
+ </para>
</listitem>
</varlistentry>
