> Can you please post an example of such a join removal? I mean a query before
> and after the removal. Thanks,
Courtesy Robert Haas:
SELECT foo.x, foo.y, foo.z FROM foo WHERE foo.x = bar.x
Conditions:
1) foo.x is not null.
2) foo (x) is a foreign key referencing bar (x).
We can ignore bar completely in this case i.e. avoid scanning bar.
Regards,
Atri
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Regards,
Atri
l'apprenant