Re: BUG #16521: n_distinct_inherited does not affect child partitions when set on main partition

On Thu, 2 Jul 2020 at 05:16, Klaudie Willis
<Klaudie.Willis@protonmail.com> wrote:
>  "n_distinct affects the statistics for the table itself, while n_distinct_inherited affects the statistics
>  gathered for the table plus its inheritance children."
>
> I see that this text has multiple interpretations. I read it more like: while n_distinct_inherited affects the
statisticsgathered [by analyze] for the table plus [affects the statistics of] its inheritance children.
 

I see. I didn't read it that way before, but it's fairly obvious now
that that's how you interpreted it.  I think there's room here to
change the documentation so that future readers are not misled.

How about?

diff --git a/doc/src/sgml/ref/alter_table.sgml
b/doc/src/sgml/ref/alter_table.sgml
index cbfb4828e5..2495564b07 100644
--- a/doc/src/sgml/ref/alter_table.sgml
+++ b/doc/src/sgml/ref/alter_table.sgml
@@ -328,8 +328,8 @@ WITH ( MODULUS <replaceable
class="parameter">numeric_literal</replaceable>, REM
       number-of-distinct-values estimates made by subsequent
       <xref linkend="sql-analyze"/>
       operations.  <literal>n_distinct</literal> affects the
statistics for the table
-      itself, while <literal>n_distinct_inherited</literal> affects
the statistics
-      gathered for the table plus its inheritance children.  When set to a
+      itself, while <literal>n_distinct_inherited</literal> affects the table's
+      inheritance statistics.  When set to a
       positive value, <command>ANALYZE</command> will assume that the
column contains
       exactly the specified number of distinct nonnull values.  When set to a
       negative value, which must be greater

David