Re: DELETE / UPDATE from partition not optimized (11.0)

On Thu, Oct 25, 2018 at 10:43:10AM -0600, Dave E Martin wrote:
> If SELECT is confident enough to limit itself to one partition, why isn't
> DELETE (or UPDATE)?

Because of this limitation:

https://www.postgresql.org/docs/current/static/ddl-partitioning.html#DDL-PARTITION-PRUNING
|Currently, pruning of partitions during the planning of an UPDATE or DELETE
|command is implemented using the constraint exclusion method (however, it is
|controlled by the enable_partition_pruning rather than constraint_exclusion) —
|see the following section for details and caveats that apply.

Justin