diff options
Diffstat (limited to 'src/backend/commands/portalcmds.c')
| -rw-r--r-- | src/backend/commands/portalcmds.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c index f65529ba6ad..4bd7ec1ba44 100644 --- a/src/backend/commands/portalcmds.c +++ b/src/backend/commands/portalcmds.c @@ -374,10 +374,23 @@ PersistHoldablePortal(Portal portal) PushActiveSnapshot(queryDesc->snapshot); /* - * Rewind the executor: we need to store the entire result set in the - * tuplestore, so that subsequent backward FETCHs can be processed. + * If the portal is marked scrollable, we need to store the entire + * result set in the tuplestore, so that subsequent backward FETCHs + * can be processed. Otherwise, store only the not-yet-fetched rows. + * (The latter is not only more efficient, but avoids semantic + * problems if the query's output isn't stable.) */ - ExecutorRewind(queryDesc); + if (portal->cursorOptions & CURSOR_OPT_SCROLL) + { + ExecutorRewind(queryDesc); + } + else + { + /* We must reset the cursor state as though at start of query */ + portal->atStart = true; + portal->atEnd = false; + portal->portalPos = 0; + } /* * Change the destination to output to the tuplestore. Note we tell |