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Diffstat (limited to 'src/backend/executor/nodeCtescan.c')
| -rw-r--r-- | src/backend/executor/nodeCtescan.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/backend/executor/nodeCtescan.c b/src/backend/executor/nodeCtescan.c index 218619c760d..24700dd3965 100644 --- a/src/backend/executor/nodeCtescan.c +++ b/src/backend/executor/nodeCtescan.c @@ -108,6 +108,13 @@ CteScanNext(CteScanState *node) } /* + * There are corner cases where the subplan could change which + * tuplestore read pointer is active, so be sure to reselect ours + * before storing the tuple we got. + */ + tuplestore_select_read_pointer(tuplestorestate, node->readptr); + + /* * Append a copy of the returned tuple to tuplestore. NOTE: because * our read pointer is certainly in EOF state, its read position will * move forward over the added tuple. This is what we want. Also, @@ -178,6 +185,12 @@ ExecInitCteScan(CteScan *node, EState *estate, int eflags) * we might be asked to rescan the CTE even though upper levels didn't * tell us to be prepared to do it efficiently. Annoying, since this * prevents truncation of the tuplestore. XXX FIXME + * + * Note: if we are in an EPQ recheck plan tree, it's likely that no access + * to the tuplestore is needed at all, making this even more annoying. + * It's not worth improving that as long as all the read pointers would + * have REWIND anyway, but if we ever improve this logic then that aspect + * should be considered too. */ eflags |= EXEC_FLAG_REWIND; |