On 12/11/19 8:49 PM, Tom Lane wrote:
Andrey Lepikhov writes:
During NestLoop execution we have bad corner case: if outer subtree
contains tuples the join node will scan inner subtree even if it does
not return any tuples.
So the first question about corner-case optimizations like this is al
Andrey Lepikhov writes:
> During NestLoop execution we have bad corner case: if outer subtree
> contains tuples the join node will scan inner subtree even if it does
> not return any tuples.
So the first question about corner-case optimizations like this is always
"how much overhead does it add
During NestLoop execution we have bad corner case: if outer subtree
contains tuples the join node will scan inner subtree even if it does
not return any tuples.
To reproduce the problem see 'problem.sql' in attachment:
Out of explain analyze see in 'problem_explain.txt'
As you can see, executo
