diff options
Diffstat (limited to 'src/include/executor/executor.h')
| -rw-r--r-- | src/include/executor/executor.h | 39 |
1 files changed, 36 insertions, 3 deletions
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h index e320a8bf926..725eed3a8cb 100644 --- a/src/include/executor/executor.h +++ b/src/include/executor/executor.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.124 2006/01/12 21:48:53 tgl Exp $ + * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.125 2006/02/28 04:10:28 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -18,6 +18,39 @@ /* + * The "eflags" argument to ExecutorStart and the various ExecInitNode + * routines is a bitwise OR of the following flag bits, which tell the + * called plan node what to expect. Note that the flags will get modified + * as they are passed down the plan tree, since an upper node may require + * functionality in its subnode not demanded of the plan as a whole + * (example: MergeJoin requires mark/restore capability in its inner input), + * or an upper node may shield its input from some functionality requirement + * (example: Materialize shields its input from needing to do backward scan). + * + * EXPLAIN_ONLY indicates that the plan tree is being initialized just so + * EXPLAIN can print it out; it will not be run. Hence, no side-effects + * of startup should occur (such as creating a SELECT INTO target table). + * However, error checks (such as permission checks) should be performed. + * + * REWIND indicates that the plan node should try to efficiently support + * rescans without parameter changes. (Nodes must support ExecReScan calls + * in any case, but if this flag was not given, they are at liberty to do it + * through complete recalculation. Note that a parameter change forces a + * full recalculation in any case.) + * + * BACKWARD indicates that the plan node must respect the es_direction flag. + * When this is not passed, the plan node will only be run forwards. + * + * MARK indicates that the plan node must support Mark/Restore calls. + * When this is not passed, no Mark/Restore will occur. + */ +#define EXEC_FLAG_EXPLAIN_ONLY 0x0001 /* EXPLAIN, no ANALYZE */ +#define EXEC_FLAG_REWIND 0x0002 /* need efficient rescan */ +#define EXEC_FLAG_BACKWARD 0x0004 /* need backward scan */ +#define EXEC_FLAG_MARK 0x0008 /* need mark/restore */ + + +/* * ExecEvalExpr was formerly a function containing a switch statement; * now it's just a macro invoking the function pointed to by an ExprState * node. Beware of double evaluation of the ExprState argument! @@ -87,7 +120,7 @@ extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot); /* * prototypes from functions in execMain.c */ -extern void ExecutorStart(QueryDesc *queryDesc, bool explainOnly); +extern void ExecutorStart(QueryDesc *queryDesc, int eflags); extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc, ScanDirection direction, long count); extern void ExecutorEnd(QueryDesc *queryDesc); @@ -103,7 +136,7 @@ extern TupleTableSlot *EvalPlanQual(EState *estate, Index rti, /* * prototypes from functions in execProcnode.c */ -extern PlanState *ExecInitNode(Plan *node, EState *estate); +extern PlanState *ExecInitNode(Plan *node, EState *estate, int eflags); extern TupleTableSlot *ExecProcNode(PlanState *node); extern Node *MultiExecProcNode(PlanState *node); extern int ExecCountSlotsNode(Plan *node); |