diff options
| -rw-r--r-- | src/backend/optimizer/prep/prepjointree.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index dbe7836b423..5a49768c6ce 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -1745,6 +1745,11 @@ reduce_outer_joins_pass2(Node *jtnode, * is that we pass either the local or the upper constraints, * never both, to the children of an outer join. * + * Note that a SEMI join works like an inner join here: it's okay + * to pass down both local and upper constraints. (There can't + * be any upper constraints affecting its inner side, but it's + * not worth having a separate code path to avoid passing them.) + * * At a FULL join we just punt and pass nothing down --- is it * possible to be smarter? */ @@ -1754,7 +1759,7 @@ reduce_outer_joins_pass2(Node *jtnode, if (!computed_local_nonnullable_vars) local_nonnullable_vars = find_nonnullable_vars(j->quals); local_forced_null_vars = find_forced_null_vars(j->quals); - if (jointype == JOIN_INNER) + if (jointype == JOIN_INNER || jointype == JOIN_SEMI) { /* OK to merge upper and local constraints */ local_nonnullable_rels = bms_add_members(local_nonnullable_rels, @@ -1774,14 +1779,14 @@ reduce_outer_joins_pass2(Node *jtnode, if (left_state->contains_outer) { - if (jointype == JOIN_INNER) + if (jointype == JOIN_INNER || jointype == JOIN_SEMI) { /* pass union of local and upper constraints */ pass_nonnullable_rels = local_nonnullable_rels; pass_nonnullable_vars = local_nonnullable_vars; pass_forced_null_vars = local_forced_null_vars; } - else if (jointype != JOIN_FULL) /* ie, LEFT/SEMI/ANTI */ + else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */ { /* can't pass local constraints to non-nullable side */ pass_nonnullable_rels = nonnullable_rels; |