From 760d328696a460deb418c8fa34b80e53fa530129 Mon Sep 17 00:00:00 2001 From: Ashutosh Bapat Date: Wed, 1 Mar 2017 13:29:51 +0530 Subject: [PATCH 3/3] GUC zap_path to enable freeing memory consumed by paths. For measuring the memory saved, add a GUC zap_path to enable/disable freeing memory occupied by paths. --- src/backend/optimizer/path/costsize.c | 1 + src/backend/optimizer/plan/planner.c | 15 +++++++++------ src/backend/utils/misc/guc.c | 10 ++++++++++ src/include/optimizer/cost.h | 1 + 4 files changed, 21 insertions(+), 6 deletions(-) diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index c138f57..f4dfa00 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -126,6 +126,7 @@ bool enable_nestloop = true; bool enable_material = true; bool enable_mergejoin = true; bool enable_hashjoin = true; +bool zap_paths = true; typedef struct { diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index 410750d..c7b085f 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -421,12 +421,15 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams) result->stmt_location = parse->stmt_location; result->stmt_len = parse->stmt_len; - /* - * We do not need paths any more, blow those away. - * TODO: probably we should also set the pathlists to NIL. - */ - MemoryContextResetAndDeleteChildren(glob->path_cxt); - glob->path_cxt = NULL; + if (zap_paths) + { + /* + * We do not need paths any more, blow those away. + * TODO: probably we should also set the pathlists to NIL. + */ + MemoryContextResetAndDeleteChildren(glob->path_cxt); + glob->path_cxt = NULL; + } MemoryContextFuncStatsEnd(CurrentMemoryContext, &mem_start, __FUNCTION__); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 2477138..630d3f7 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -912,6 +912,16 @@ static struct config_bool ConfigureNamesBool[] = true, NULL, NULL, NULL }, + + { + {"zap_paths", PGC_USERSET, QUERY_TUNING_GEQO, + gettext_noop("Free up the memory used by paths at the end of planning."), + }, + &zap_paths, + true, + NULL, NULL, NULL + }, + { /* Not for general use --- used by SET SESSION AUTHORIZATION */ {"is_superuser", PGC_INTERNAL, UNGROUPED, diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h index 72200fa..fc882ad 100644 --- a/src/include/optimizer/cost.h +++ b/src/include/optimizer/cost.h @@ -67,6 +67,7 @@ extern bool enable_material; extern bool enable_mergejoin; extern bool enable_hashjoin; extern int constraint_exclusion; +extern bool zap_paths; extern double clamp_row_est(double nrows); extern double index_pages_fetched(double tuples_fetched, BlockNumber pages, -- 1.7.9.5