On 08/10/2018 10:22, David Rowley wrote:
> Before 5220bb7533f a note in ddl.sgml used to mention that run-time
> pruning was only implemented for Append. When we got MergeAppend
> support the commit updated this to mention MergeAppend is supported
> too. This is slightly weird as it's not all that obvious what exactly
> isn't supported when we mention:
>
> <para>
> Both of these behaviors are likely to be changed in a future release
> of <productname>PostgreSQL</productname>.
> </para>
>
> The attached patch updates this to mention that ModifyTable is
> unsupported which I think makes the above fragment make sense again.
<para>
- Execution-time partition pruning currently occurs for the
+ Execution-time partition pruning currently only occurs for the
<literal>Append</literal> and <literal>MergeAppend</literal> node
types.
+ It is not yet implemented for the <literal>ModifyTable</literal> node
+ type.
</para>
Isn't this implied by the preceding paragraph
Currently, pruning of partitions during the planning of an UPDATE or
DELETE command is implemented using the constraint exclusion method
?
Also, could there be other node types that could benefit from partition
pruning that are not implemented yet? Not sure we want to mention all
of them.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services