diff options
| -rw-r--r-- | src/backend/optimizer/plan/planmain.c | 55 |
1 files changed, 50 insertions, 5 deletions
diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c index a33d068a385..6b6bc15bda7 100644 --- a/src/backend/optimizer/plan/planmain.c +++ b/src/backend/optimizer/plan/planmain.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.56 2000/07/24 03:11:01 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.57 2000/07/27 04:51:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -28,6 +28,7 @@ #include "optimizer/paths.h" #include "optimizer/planmain.h" #include "optimizer/tlist.h" +#include "utils/memutils.h" static Plan *subplanner(Query *root, List *flat_tlist, List *qual, @@ -176,6 +177,9 @@ subplanner(Query *root, double tuple_fraction) { RelOptInfo *final_rel; + Plan *resultplan; + MemoryContext mycontext; + MemoryContext oldcxt; Path *cheapestpath; Path *presortedpath; @@ -213,6 +217,24 @@ subplanner(Query *root, root->query_pathkeys = canonicalize_pathkeys(root, root->query_pathkeys); /* + * We might allocate quite a lot of storage during planning (due to + * constructing lots of Paths), but all of it can be reclaimed after + * we generate the finished Plan tree. Work in a temporary context + * to let that happen. We make the context a child of + * TransactionCommandContext so it will be freed if error abort. + * + * Note: beware of trying to move this up to the start of this routine. + * Some of the data structures built above --- notably the pathkey + * equivalence sets --- will still be needed after this routine exits. + */ + mycontext = AllocSetContextCreate(TransactionCommandContext, + "Planner", + ALLOCSET_DEFAULT_MINSIZE, + ALLOCSET_DEFAULT_INITSIZE, + ALLOCSET_DEFAULT_MAXSIZE); + oldcxt = MemoryContextSwitchTo(mycontext); + + /* * Ready to do the primary planning. */ final_rel = make_one_rel(root); @@ -235,7 +257,9 @@ subplanner(Query *root, root->query_pathkeys = NIL; /* signal unordered result */ /* Make childless Result node to evaluate given tlist. */ - return (Plan *) make_result(flat_tlist, (Node *) qual, (Plan *) NULL); + resultplan = (Plan *) make_result(flat_tlist, (Node *) qual, + (Plan *) NULL); + goto plan_built; } #ifdef NOT_USED /* fix xfunc */ @@ -295,7 +319,8 @@ subplanner(Query *root, cheapestpath->pathkeys)) { root->query_pathkeys = cheapestpath->pathkeys; - return create_plan(root, cheapestpath); + resultplan = create_plan(root, cheapestpath); + goto plan_built; } /* @@ -321,7 +346,8 @@ subplanner(Query *root, { /* Presorted path is cheaper, use it */ root->query_pathkeys = presortedpath->pathkeys; - return create_plan(root, presortedpath); + resultplan = create_plan(root, presortedpath); + goto plan_built; } /* otherwise, doing it the hard way is still cheaper */ } @@ -334,5 +360,24 @@ subplanner(Query *root, * as an aggregate function...) */ root->query_pathkeys = cheapestpath->pathkeys; - return create_plan(root, cheapestpath); + resultplan = create_plan(root, cheapestpath); + +plan_built: + + /* + * Must copy the completed plan tree and its pathkeys out of temporary + * context. + */ + MemoryContextSwitchTo(oldcxt); + + resultplan = copyObject(resultplan); + + root->query_pathkeys = copyObject(root->query_pathkeys); + + /* + * Now we can release the Path storage. + */ + MemoryContextDelete(mycontext); + + return resultplan; } |