On 4 December 2014 at 12:24, Simon Riggs <simon@2ndquadrant.com> wrote:
> On 3 December 2014 at 12:18, Atri Sharma <atri.jiit@gmail.com> wrote:
>
>> So the planner keeps all possibility satisfying plans, or it looks at the
>> possible conditions (like presence of foreign key for this case, for eg) and
>> then lets executor choose between them?
>
> I'm suggesting the planner keeps 2 plans: One with removable joins,
> one without the removable joins.
I only just noticed the thread moved on while I was flying.
So it looks Tom and I said the same thing, or close enough for me to +1 Tom.
Another idea would be to only skip Hash and Merge Joins, since the
tests for those are fairly easy to put into the Init call. That sounds
slightly easier than the proposal with the Option/Choice/Switch node.
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services