diff options
Diffstat (limited to 'src/backend/executor/execMain.c')
| -rw-r--r-- | src/backend/executor/execMain.c | 74 |
1 files changed, 25 insertions, 49 deletions
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c index 49fa4156de4..47840d42ebc 100644 --- a/src/backend/executor/execMain.c +++ b/src/backend/executor/execMain.c @@ -26,7 +26,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.313 2008/08/25 22:42:32 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.314 2008/10/31 21:07:54 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -76,7 +76,7 @@ typedef struct evalPlanQual static void InitPlan(QueryDesc *queryDesc, int eflags); static void ExecCheckPlanOutput(Relation resultRel, List *targetList); static void ExecEndPlan(PlanState *planstate, EState *estate); -static TupleTableSlot *ExecutePlan(EState *estate, PlanState *planstate, +static void ExecutePlan(EState *estate, PlanState *planstate, CmdType operation, long numberTuples, ScanDirection direction, @@ -220,26 +220,28 @@ ExecutorStart(QueryDesc *queryDesc, int eflags) * Note: count = 0 is interpreted as no portal limit, i.e., run to * completion. * + * There is no return value, but output tuples (if any) are sent to + * the destination receiver specified in the QueryDesc; and the number + * of tuples processed at the top level can be found in + * estate->es_processed. + * * We provide a function hook variable that lets loadable plugins * get control when ExecutorRun is called. Such a plugin would * normally call standard_ExecutorRun(). * * ---------------------------------------------------------------- */ -TupleTableSlot * +void ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count) { - TupleTableSlot *result; - if (ExecutorRun_hook) - result = (*ExecutorRun_hook) (queryDesc, direction, count); + (*ExecutorRun_hook) (queryDesc, direction, count); else - result = standard_ExecutorRun(queryDesc, direction, count); - return result; + standard_ExecutorRun(queryDesc, direction, count); } -TupleTableSlot * +void standard_ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count) { @@ -247,7 +249,6 @@ standard_ExecutorRun(QueryDesc *queryDesc, CmdType operation; DestReceiver *dest; bool sendTuples; - TupleTableSlot *result; MemoryContext oldcontext; /* sanity checks */ @@ -283,15 +284,13 @@ standard_ExecutorRun(QueryDesc *queryDesc, /* * run plan */ - if (ScanDirectionIsNoMovement(direction)) - result = NULL; - else - result = ExecutePlan(estate, - queryDesc->planstate, - operation, - count, - direction, - dest); + if (!ScanDirectionIsNoMovement(direction)) + ExecutePlan(estate, + queryDesc->planstate, + operation, + count, + direction, + dest); /* * shutdown tuple receiver, if we started it @@ -300,8 +299,6 @@ standard_ExecutorRun(QueryDesc *queryDesc, (*dest->rShutdown) (dest); MemoryContextSwitchTo(oldcontext); - - return result; } /* ---------------------------------------------------------------- @@ -1271,19 +1268,16 @@ ExecEndPlan(PlanState *planstate, EState *estate) /* ---------------------------------------------------------------- * ExecutePlan * - * processes the query plan to retrieve 'numberTuples' tuples in the - * direction specified. - * - * Retrieves all tuples if numberTuples is 0 + * Processes the query plan until we have processed 'numberTuples' tuples, + * moving in the specified direction. * - * result is either a slot containing the last tuple in the case - * of a SELECT or NULL otherwise. + * Runs to completion if numberTuples is 0 * * Note: the ctid attribute is a 'junk' attribute that is removed before the * user can see it * ---------------------------------------------------------------- */ -static TupleTableSlot * +static void ExecutePlan(EState *estate, PlanState *planstate, CmdType operation, @@ -1297,13 +1291,11 @@ ExecutePlan(EState *estate, ItemPointer tupleid = NULL; ItemPointerData tuple_ctid; long current_tuple_count; - TupleTableSlot *result; /* * initialize local variables */ current_tuple_count = 0; - result = NULL; /* * Set the direction. @@ -1332,7 +1324,6 @@ ExecutePlan(EState *estate, /* * Loop until we've processed the proper number of tuples from the plan. */ - for (;;) { /* Reset the per-output-tuple exprcontext */ @@ -1353,13 +1344,10 @@ lnext: ; /* * if the tuple is null, then we assume there is nothing more to - * process so we just return null... + * process so we just end the loop... */ if (TupIsNull(planSlot)) - { - result = NULL; break; - } slot = planSlot; /* @@ -1453,7 +1441,6 @@ lnext: ; default: elog(ERROR, "unrecognized heap_lock_tuple status: %u", test); - return NULL; } } } @@ -1488,35 +1475,30 @@ lnext: ; /* * now that we have a tuple, do the appropriate thing with it.. either - * return it to the user, add it to a relation someplace, delete it - * from a relation, or modify some of its attributes. + * send it to the output destination, add it to a relation someplace, + * delete it from a relation, or modify some of its attributes. */ switch (operation) { case CMD_SELECT: ExecSelect(slot, dest, estate); - result = slot; break; case CMD_INSERT: ExecInsert(slot, tupleid, planSlot, dest, estate); - result = NULL; break; case CMD_DELETE: ExecDelete(tupleid, planSlot, dest, estate); - result = NULL; break; case CMD_UPDATE: ExecUpdate(slot, tupleid, planSlot, dest, estate); - result = NULL; break; default: elog(ERROR, "unrecognized operation code: %d", (int) operation); - result = NULL; break; } @@ -1548,12 +1530,6 @@ lnext: ; /* do nothing */ break; } - - /* - * here, result is either a slot containing a tuple in the case of a - * SELECT or NULL otherwise. - */ - return result; } /* ---------------------------------------------------------------- |