diff options
Diffstat (limited to 'src/backend/executor/nodeMaterial.c')
| -rw-r--r-- | src/backend/executor/nodeMaterial.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c index 494560d0f46..baf8a99717e 100644 --- a/src/backend/executor/nodeMaterial.c +++ b/src/backend/executor/nodeMaterial.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.63 2008/10/01 19:51:49 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeMaterial.c,v 1.64 2008/12/27 17:39:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -66,11 +66,11 @@ ExecMaterial(MaterialState *node) * Allocate a second read pointer to serve as the mark. * We know it must have index 1, so needn't store that. */ - int ptrn; + int ptrno; - ptrn = tuplestore_alloc_read_pointer(tuplestorestate, - node->eflags); - Assert(ptrn == 1); + ptrno = tuplestore_alloc_read_pointer(tuplestorestate, + node->eflags); + Assert(ptrno == 1); } node->tuplestorestate = tuplestorestate; } @@ -182,6 +182,16 @@ ExecInitMaterial(Material *node, EState *estate, int eflags) EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)); + /* + * Tuplestore's interpretation of the flag bits is subtly different from + * the general executor meaning: it doesn't think BACKWARD necessarily + * means "backwards all the way to start". If told to support BACKWARD we + * must include REWIND in the tuplestore eflags, else tuplestore_trim + * might throw away too much. + */ + if (eflags & EXEC_FLAG_BACKWARD) + matstate->eflags |= EXEC_FLAG_REWIND; + matstate->eof_underlying = false; matstate->tuplestorestate = NULL; @@ -278,6 +288,11 @@ ExecMaterialMarkPos(MaterialState *node) * copy the active read pointer to the mark. */ tuplestore_copy_read_pointer(node->tuplestorestate, 0, 1); + + /* + * since we may have advanced the mark, try to truncate the tuplestore. + */ + tuplestore_trim(node->tuplestorestate); } /* ---------------------------------------------------------------- |