1414 *
1515 *
1616 * IDENTIFICATION
17- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.56 2000/07/24 03:11:01 tgl Exp $
17+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.57 2000/07/27 04:51:04 tgl Exp $
1818 *
1919 *-------------------------------------------------------------------------
2020 */
2828#include "optimizer/paths.h"
2929#include "optimizer/planmain.h"
3030#include "optimizer/tlist.h"
31+ #include "utils/memutils.h"
3132
3233
3334static Plan * subplanner (Query * root ,List * flat_tlist ,List * qual ,
@@ -176,6 +177,9 @@ subplanner(Query *root,
176177double tuple_fraction )
177178{
178179RelOptInfo * final_rel ;
180+ Plan * resultplan ;
181+ MemoryContext mycontext ;
182+ MemoryContext oldcxt ;
179183Path * cheapestpath ;
180184Path * presortedpath ;
181185
@@ -212,6 +216,24 @@ subplanner(Query *root,
212216 */
213217root -> query_pathkeys = canonicalize_pathkeys (root ,root -> query_pathkeys );
214218
219+ /*
220+ * We might allocate quite a lot of storage during planning (due to
221+ * constructing lots of Paths), but all of it can be reclaimed after
222+ * we generate the finished Plan tree. Work in a temporary context
223+ * to let that happen. We make the context a child of
224+ * TransactionCommandContext so it will be freed if error abort.
225+ *
226+ * Note: beware of trying to move this up to the start of this routine.
227+ * Some of the data structures built above --- notably the pathkey
228+ * equivalence sets --- will still be needed after this routine exits.
229+ */
230+ mycontext = AllocSetContextCreate (TransactionCommandContext ,
231+ "Planner" ,
232+ ALLOCSET_DEFAULT_MINSIZE ,
233+ ALLOCSET_DEFAULT_INITSIZE ,
234+ ALLOCSET_DEFAULT_MAXSIZE );
235+ oldcxt = MemoryContextSwitchTo (mycontext );
236+
215237/*
216238 * Ready to do the primary planning.
217239 */
@@ -235,7 +257,9 @@ subplanner(Query *root,
235257root -> query_pathkeys = NIL ;/* signal unordered result */
236258
237259/* Make childless Result node to evaluate given tlist. */
238- return (Plan * )make_result (flat_tlist , (Node * )qual , (Plan * )NULL );
260+ resultplan = (Plan * )make_result (flat_tlist , (Node * )qual ,
261+ (Plan * )NULL );
262+ gotoplan_built ;
239263}
240264
241265#ifdef NOT_USED /* fix xfunc */
@@ -295,7 +319,8 @@ subplanner(Query *root,
295319cheapestpath -> pathkeys ))
296320{
297321root -> query_pathkeys = cheapestpath -> pathkeys ;
298- return create_plan (root ,cheapestpath );
322+ resultplan = create_plan (root ,cheapestpath );
323+ gotoplan_built ;
299324}
300325
301326/*
@@ -321,7 +346,8 @@ subplanner(Query *root,
321346{
322347/* Presorted path is cheaper, use it */
323348root -> query_pathkeys = presortedpath -> pathkeys ;
324- return create_plan (root ,presortedpath );
349+ resultplan = create_plan (root ,presortedpath );
350+ gotoplan_built ;
325351}
326352/* otherwise, doing it the hard way is still cheaper */
327353}
@@ -334,5 +360,24 @@ subplanner(Query *root,
334360 * as an aggregate function...)
335361 */
336362root -> query_pathkeys = cheapestpath -> pathkeys ;
337- return create_plan (root ,cheapestpath );
363+ resultplan = create_plan (root ,cheapestpath );
364+
365+ plan_built :
366+
367+ /*
368+ * Must copy the completed plan tree and its pathkeys out of temporary
369+ * context.
370+ */
371+ MemoryContextSwitchTo (oldcxt );
372+
373+ resultplan = copyObject (resultplan );
374+
375+ root -> query_pathkeys = copyObject (root -> query_pathkeys );
376+
377+ /*
378+ * Now we can release the Path storage.
379+ */
380+ MemoryContextDelete (mycontext );
381+
382+ return resultplan ;
338383}