Richard Guo writes:
> On Tue, Feb 7, 2023 at 2:12 PM Tom Lane wrote:
>> I don't see any change in this query plan when I remove that code, so
>> I'm not sure you're explaining your point very well.
> To observe an obvious plan change, we can add unique constraint for 'a'
> and look how outer-joi
On Tue, Feb 7, 2023 at 2:12 PM Tom Lane wrote:
> Richard Guo writes:
> > I noticed this code because I came across a problem with a query as
> > below.
>
> > create table t (a int);
>
> > select t1.a from (t t1 left join t t2 on true) left join (t t3 left join
> t
> > t4 on t3.a = t4.a) on t2.a
Richard Guo writes:
> In deconstruct_distribute_oj_quals, when we've identified a commutable
> left join which provides join clause with flexible semantics, we try to
> generate multiple versions of the join clause. Here we have the logic
> that puts back any ojrelids that were removed from its m
In deconstruct_distribute_oj_quals, when we've identified a commutable
left join which provides join clause with flexible semantics, we try to
generate multiple versions of the join clause. Here we have the logic
that puts back any ojrelids that were removed from its min_righthand.
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