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| author | Robert Haas <rhaas@postgresql.org> | 2016-06-06 14:52:58 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2016-06-06 14:52:58 -0400 |
| commit | c6dbf1fe79287291bc260cbc06b0de419d2a198c (patch) | |
| tree | 8edc5d8f7d13201c73d90f0c217f6e00a27e5099 /src/backend/executor/functions.c | |
| parent | 44339b892a04e94bbb472235882dc6f7023bdc65 (diff) | |
| download | postgresql-c6dbf1fe79287291bc260cbc06b0de419d2a198c.tar.gz postgresql-c6dbf1fe79287291bc260cbc06b0de419d2a198c.zip | |
Stop the executor if no more tuples can be sent from worker to leader.
If a Gather node has read as many tuples as it needs (for example, due
to Limit) it may detach the queue connecting it to the worker before
reading all of the worker's tuples. Rather than let the worker
continue to generate and send all of the results, have it stop after
sending the next tuple.
More could be done here to stop the worker even quicker, but this is
about as well as we can hope to do for 9.6.
This is in response to a problem report from Andreas Seltenreich.
Commit 44339b892a04e94bbb472235882dc6f7023bdc65 should be actually be
sufficient to fix that example even without this change, but it seems
better to do this, too, since we might otherwise waste quite a large
amount of effort in one or more workers.
Discussion: CAA4eK1KOKGqmz9bGu+Z42qhRwMbm4R5rfnqsLCNqFs9j14jzEA@mail.gmail.com
Amit Kapila
Diffstat (limited to 'src/backend/executor/functions.c')
| -rw-r--r-- | src/backend/executor/functions.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c index 6e14c9d2967..cd93c045dcb 100644 --- a/src/backend/executor/functions.c +++ b/src/backend/executor/functions.c @@ -167,7 +167,7 @@ static Datum postquel_get_single_result(TupleTableSlot *slot, static void sql_exec_error_callback(void *arg); static void ShutdownSQLFunction(Datum arg); static void sqlfunction_startup(DestReceiver *self, int operation, TupleDesc typeinfo); -static void sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self); +static bool sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self); static void sqlfunction_shutdown(DestReceiver *self); static void sqlfunction_destroy(DestReceiver *self); @@ -1904,7 +1904,7 @@ sqlfunction_startup(DestReceiver *self, int operation, TupleDesc typeinfo) /* * sqlfunction_receive --- receive one tuple */ -static void +static bool sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self) { DR_sqlfunction *myState = (DR_sqlfunction *) self; @@ -1914,6 +1914,8 @@ sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self) /* Store the filtered tuple into the tuplestore */ tuplestore_puttupleslot(myState->tstore, slot); + + return true; } /* |