On Tue, Apr 17, 2018 at 5:42 PM, Justin Pryzby <pry...@telsasoft.com> wrote:
> On Wed, Apr 18, 2018 at 12:07:18PM +1200, David Rowley wrote: > > In PG10 the planner's partition pruning could be disabled by changing > > the constraint_exclusion GUC to off. This is still the case for PG11, > > but only for UPDATE and DELETE queries. There is currently no way to > > disable partition pruning for SELECT. > > > > Should we allow this? > > > 3. No new GUCs / Do nothing. > > Maybe this is divergent from the details of the implementation; but, from a > user's perspective: why not continue to use constraint_exclusion? > > I would suggest to add zero new GUCs: > > 0. constraint_exclusion={off,partition,on,PLANNER*,EXECUTOR*} > My initial reaction is that we need to fix the bug introduced in v10 - leaving constraint_exclusion working as it has historically and not affect the new-as-of-10 ability to prune (maybe better termed as skip...) partitions known during execution to contain no qualified tuples. David J.