diff options
Diffstat (limited to 'src/backend/executor/nodeHashjoin.c')
| -rw-r--r-- | src/backend/executor/nodeHashjoin.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/backend/executor/nodeHashjoin.c b/src/backend/executor/nodeHashjoin.c index f2c885afbe2..40419c88914 100644 --- a/src/backend/executor/nodeHashjoin.c +++ b/src/backend/executor/nodeHashjoin.c @@ -288,10 +288,11 @@ ExecHashJoin(HashJoinState *node) } /* - * In a semijoin, we'll consider returning the first - * match, but after that we're done with this outer tuple. + * If we only need to join to the first matching inner + * tuple, then consider returning this one, but after that + * continue with next outer tuple. */ - if (node->js.jointype == JOIN_SEMI) + if (node->js.single_match) node->hj_JoinState = HJ_NEED_NEW_OUTER; if (otherqual == NULL || ExecQual(otherqual, econtext)) @@ -435,6 +436,12 @@ ExecInitHashJoin(HashJoin *node, EState *estate, int eflags) ExecInitResultTupleSlot(estate, &hjstate->js.ps); hjstate->hj_OuterTupleSlot = ExecInitExtraTupleSlot(estate); + /* + * detect whether we need only consider the first matching inner tuple + */ + hjstate->js.single_match = (node->join.inner_unique || + node->join.jointype == JOIN_SEMI); + /* set up null tuples for outer joins, if needed */ switch (node->join.jointype) { |