Re: Should we add GUCs to allow partition pruning to be disabled?

On 2018/04/20 15:00, Ashutosh Bapat wrote:
> On Fri, Apr 20, 2018 at 7:37 AM, Amit Langote wrote:
>> On 2018/04/19 21:50, Ashutosh Bapat wrote:
>>> There's no point in confusing users
>>> with by adding dependencies between these two GUCs.
>>
>> That's exactly what I'm trying to propose.
>
> Not really. By pruning based on the partition bounds I didn't mean
> constraint exclusion working on partition bound based constraints.

Sorry, I should have said what I said after quoting only the last sentence
of what you had said. That is, I want to the new GUC to be the only
determiner of whether the pruning occurs or not for partitioned tables.
To implement that behavior, it will have to override the setting of
constraint_exclusion (the parameter) in *some* cases, because some
commands still rely on constraint exclusion (the algorithm) as the
underlying pruning mechanism. Now, the "override the setting of
constraint_exclusion" implementation may not be the most popular choice in
the end.

Thanks,
Amit