diff options
Diffstat (limited to 'src/backend/executor/nodeMergejoin.c')
| -rw-r--r-- | src/backend/executor/nodeMergejoin.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/src/backend/executor/nodeMergejoin.c b/src/backend/executor/nodeMergejoin.c index e3b736f9079..948f5800958 100644 --- a/src/backend/executor/nodeMergejoin.c +++ b/src/backend/executor/nodeMergejoin.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.102 2010/05/28 01:14:03 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.103 2010/07/06 19:18:56 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -252,7 +252,7 @@ MJExamineQuals(List *mergeclauses, * input, since we assume mergejoin operators are strict. If the NULL * is in the first join column, and that column sorts nulls last, then * we can further conclude that no following tuple can match anything - * either, since they must all have nulls in the first column. However, + * either, since they must all have nulls in the first column. However, * that case is only interesting if we're not in FillOuter mode, else * we have to visit all the tuples anyway. * @@ -748,6 +748,7 @@ ExecMergeJoin(MergeJoinState *node) switch (MJEvalInnerValues(node, innerTupleSlot)) { case MJEVAL_MATCHABLE: + /* * OK, we have the initial tuples. Begin by skipping * non-matching tuples. @@ -922,6 +923,7 @@ ExecMergeJoin(MergeJoinState *node) switch (MJEvalInnerValues(node, innerTupleSlot)) { case MJEVAL_MATCHABLE: + /* * Test the new inner tuple to see if it matches * outer. @@ -944,6 +946,7 @@ ExecMergeJoin(MergeJoinState *node) } break; case MJEVAL_NONMATCHABLE: + /* * It contains a NULL and hence can't match any outer * tuple, so we can skip the comparison and assume the @@ -952,10 +955,11 @@ ExecMergeJoin(MergeJoinState *node) node->mj_JoinState = EXEC_MJ_NEXTOUTER; break; case MJEVAL_ENDOFJOIN: + /* - * No more inner tuples. However, this might be - * only effective and not physical end of inner plan, - * so force mj_InnerTupleSlot to null to make sure we + * No more inner tuples. However, this might be only + * effective and not physical end of inner plan, so + * force mj_InnerTupleSlot to null to make sure we * don't fetch more inner tuples. (We need this hack * because we are not transiting to a state where the * inner plan is assumed to be exhausted.) @@ -1152,9 +1156,11 @@ ExecMergeJoin(MergeJoinState *node) node->mj_JoinState = EXEC_MJ_SKIP_TEST; break; case MJEVAL_NONMATCHABLE: + /* * current inner can't possibly match any outer; - * better to advance the inner scan than the outer. + * better to advance the inner scan than the + * outer. */ node->mj_JoinState = EXEC_MJ_SKIPINNER_ADVANCE; break; @@ -1337,6 +1343,7 @@ ExecMergeJoin(MergeJoinState *node) node->mj_JoinState = EXEC_MJ_SKIP_TEST; break; case MJEVAL_NONMATCHABLE: + /* * current inner can't possibly match any outer; * better to advance the inner scan than the outer. |