On 5/1/24 18:59, Alexander Korotkov wrote:
> I think we probably could forbid SJE for the tables with TABLESAMPLE
> altogether. Please, check the attached patch.
Your patch looks good to me. I added some comments and test case into
the join.sql.
One question for me is: Do we anticipate other lateral self-references
except the TABLESAMPLE case? Looking into the extract_lateral_references
implementation, I see the only RTE_SUBQUERY case to be afraid of. But we
pull up subqueries before extracting lateral references. So, if we have
a reference to a subquery, it means we will not flatten this subquery
and don't execute SJE. Do we need more code, as you have written in the
first patch?
--
regards,
Andrei Lepikhov
Postgres Professional