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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2023-12-05 22:53:12 +0200 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2023-12-05 22:53:12 +0200 |
| commit | 824dbea3e41efa3b35094163c834988dea7eb139 (patch) | |
| tree | f810eb49e750dee3b601385328faa0f4369291f6 /contrib/postgres_fdw/postgres_fdw.h | |
| parent | 278eb13c48236c261ed4bab1cb4696321e346eb7 (diff) | |
| download | postgresql-824dbea3e41efa3b35094163c834988dea7eb139.tar.gz postgresql-824dbea3e41efa3b35094163c834988dea7eb139.zip | |
Add support for deparsing semi-joins to contrib/postgres_fdw
SEMI-JOIN is deparsed as the EXISTS subquery. It references outer and inner
relations, so it should be evaluated as the condition in the upper-level WHERE
clause. The signatures of deparseFromExprForRel() and deparseRangeTblRef() are
revised so that they can add conditions to the upper level.
PgFdwRelationInfo now has a hidden_subquery_rels field, referencing the relids
used in the inner parts of semi-join. They can't be referred to from upper
relations and should be used internally for equivalence member searches.
The planner can create semi-join, which refers to inner rel vars in its target
list. However, we deparse semi-join as an exists() subquery. So we skip the
case when the target list references to inner rel of semi-join.
Author: Alexander Pyhalov
Reviewed-by: Ashutosh Bapat, Ian Lawrence Barwick, Yuuki Fujii, Tomas Vondra
Discussion: https://postgr.es/m/c9e2a757cf3ac2333714eaf83a9cc184@postgrespro.ru
Diffstat (limited to 'contrib/postgres_fdw/postgres_fdw.h')
| -rw-r--r-- | contrib/postgres_fdw/postgres_fdw.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/postgres_fdw.h b/contrib/postgres_fdw/postgres_fdw.h index 47157ac887e..9a1a80aebb4 100644 --- a/contrib/postgres_fdw/postgres_fdw.h +++ b/contrib/postgres_fdw/postgres_fdw.h @@ -118,6 +118,10 @@ typedef struct PgFdwRelationInfo * subquery? */ Relids lower_subquery_rels; /* all relids appearing in lower * subqueries */ + Relids hidden_subquery_rels; /* relids, which can't be referred to + * from upper relations, used + * internally for equivalence member + * search */ /* * Index of the relation. It is used to create an alias to a subquery |