From 4bea6a4d150b694f3d16546ec865e4be948745ed Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Villemain?= Date: Thu, 2 Jun 2011 02:28:01 +0200 Subject: [PATCH 6/7] Add cache_page_cost GUC this is used to improve cache estimate and impact in IO cost estimations --- doc/src/sgml/config.sgml | 13 +++++++++++++ src/backend/optimizer/path/costsize.c | 1 + src/backend/utils/misc/guc.c | 10 ++++++++++ src/backend/utils/misc/postgresql.conf.sample | 1 + src/include/optimizer/cost.h | 2 ++ 5 files changed, 27 insertions(+), 0 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml new file mode 100644 index e835e4b..8bc5560 *** a/doc/src/sgml/config.sgml --- b/doc/src/sgml/config.sgml *************** SET ENABLE_SEQSCAN TO OFF; *** 2514,2519 **** --- 2514,2532 ---- + + cache_page_cost (floating point) + + cache_page_cost configuration parameter + + + + Sets the planner's estimate of the cost of a + fetched page from cache. The default is 0.1. + + + + cpu_tuple_cost (floating point) diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c new file mode 100644 index bb38768..a80dc0c *** a/src/backend/optimizer/path/costsize.c --- b/src/backend/optimizer/path/costsize.c *************** *** 100,105 **** --- 100,106 ---- double seq_page_cost = DEFAULT_SEQ_PAGE_COST; double random_page_cost = DEFAULT_RANDOM_PAGE_COST; + double cache_page_cost = DEFAULT_CACHE_PAGE_COST; double cpu_tuple_cost = DEFAULT_CPU_TUPLE_COST; double cpu_index_tuple_cost = DEFAULT_CPU_INDEX_TUPLE_COST; double cpu_operator_cost = DEFAULT_CPU_OPERATOR_COST; diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c new file mode 100644 index 92391ed..7465c08 *** a/src/backend/utils/misc/guc.c --- b/src/backend/utils/misc/guc.c *************** static struct config_real ConfigureNames *** 2392,2397 **** --- 2392,2407 ---- NULL, NULL, NULL }, { + {"cache_page_cost", PGC_USERSET, QUERY_TUNING_COST, + gettext_noop("Sets the planner's estimate of the cost of a " + "fetched page from cache."), + NULL + }, + &cache_page_cost, + DEFAULT_CACHE_PAGE_COST, 0, DBL_MAX, + NULL, NULL, NULL + }, + { {"cpu_tuple_cost", PGC_USERSET, QUERY_TUNING_COST, gettext_noop("Sets the planner's estimate of the cost of " "processing each tuple (row)."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample new file mode 100644 index 655dad4..82159e1 *** a/src/backend/utils/misc/postgresql.conf.sample --- b/src/backend/utils/misc/postgresql.conf.sample *************** *** 233,238 **** --- 233,239 ---- #seq_page_cost = 1.0 # measured on an arbitrary scale #random_page_cost = 4.0 # same scale as above + #cache_page_cost = 0.1 # same scale as above #cpu_tuple_cost = 0.01 # same scale as above #cpu_index_tuple_cost = 0.005 # same scale as above #cpu_operator_cost = 0.0025 # same scale as above diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h new file mode 100644 index 2763863..f4babd0 *** a/src/include/optimizer/cost.h --- b/src/include/optimizer/cost.h *************** *** 23,28 **** --- 23,29 ---- /* If you change these, update backend/utils/misc/postgresql.sample.conf */ #define DEFAULT_SEQ_PAGE_COST 1.0 #define DEFAULT_RANDOM_PAGE_COST 4.0 + #define DEFAULT_CACHE_PAGE_COST 0.1 #define DEFAULT_CPU_TUPLE_COST 0.01 #define DEFAULT_CPU_INDEX_TUPLE_COST 0.005 #define DEFAULT_CPU_OPERATOR_COST 0.0025 *************** typedef enum *** 45,50 **** --- 46,52 ---- /* parameter variables and flags */ extern PGDLLIMPORT double seq_page_cost; extern PGDLLIMPORT double random_page_cost; + extern PGDLLIMPORT double cache_page_cost; extern PGDLLIMPORT double cpu_tuple_cost; extern PGDLLIMPORT double cpu_index_tuple_cost; extern PGDLLIMPORT double cpu_operator_cost; -- 1.7.5.3