diff options
Diffstat (limited to 'src/backend/utils')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 6 | ||||
| -rw-r--r-- | src/backend/utils/misc/guc.c | 54 | ||||
| -rw-r--r-- | src/backend/utils/misc/postgresql.conf.sample | 10 |
3 files changed, 38 insertions, 32 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 5aeadce0917..c75ceef3732 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -15,7 +15,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.205 2006/05/02 11:28:55 teodor Exp $ + * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.206 2006/06/05 02:49:58 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -4555,9 +4555,9 @@ genericcostestimate(PlannerInfo *root, * Compute the index access cost. * * Disk cost: our generic assumption is that the index pages will be read - * sequentially, so they have cost 1.0 each, not random_page_cost. + * sequentially, so they cost seq_page_cost each, not random_page_cost. */ - *indexTotalCost = numIndexPages; + *indexTotalCost = seq_page_cost * numIndexPages; /* * CPU cost: any complex expressions in the indexquals will need to be diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 1ff2e0c8318..9ef561d4c12 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -10,7 +10,7 @@ * Written by Peter Eisentraut <peter_e@gmx.net>. * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.320 2006/05/21 20:10:42 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.321 2006/06/05 02:49:58 tgl Exp $ * *-------------------------------------------------------------------- */ @@ -1595,57 +1595,63 @@ static struct config_int ConfigureNamesInt[] = static struct config_real ConfigureNamesReal[] = { { - {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST, - gettext_noop("Sets the planner's assumption about size of the disk cache."), - gettext_noop("That is, the portion of the kernel's disk cache that " - "will be used for PostgreSQL data files. This is measured in disk " - "pages, which are normally 8 kB each.") + {"seq_page_cost", PGC_USERSET, QUERY_TUNING_COST, + gettext_noop("Sets the planner's estimate of the cost of a " + "sequentially fetched disk page."), + NULL }, - &effective_cache_size, - DEFAULT_EFFECTIVE_CACHE_SIZE, 1, DBL_MAX, NULL, NULL + &seq_page_cost, + DEFAULT_SEQ_PAGE_COST, 0, DBL_MAX, NULL, NULL }, { {"random_page_cost", PGC_USERSET, QUERY_TUNING_COST, - gettext_noop("Sets the planner's estimate of the cost of a nonsequentially " - "fetched disk page."), - gettext_noop("This is measured as a multiple of the cost of a " - "sequential page fetch. A higher value makes it more likely a " - "sequential scan will be used, a lower value makes it more likely an " - "index scan will be used.") + gettext_noop("Sets the planner's estimate of the cost of a " + "nonsequentially fetched disk page."), + NULL }, &random_page_cost, DEFAULT_RANDOM_PAGE_COST, 0, DBL_MAX, 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)."), - gettext_noop("This is measured as a fraction of the cost of a " - "sequential page fetch.") + gettext_noop("Sets the planner's estimate of the cost of " + "processing each tuple (row)."), + NULL }, &cpu_tuple_cost, DEFAULT_CPU_TUPLE_COST, 0, DBL_MAX, NULL, NULL }, { {"cpu_index_tuple_cost", PGC_USERSET, QUERY_TUNING_COST, - gettext_noop("Sets the planner's estimate of processing cost for each " - "index tuple (row) during index scan."), - gettext_noop("This is measured as a fraction of the cost of a " - "sequential page fetch.") + gettext_noop("Sets the planner's estimate of the cost of " + "processing each index entry during an index scan."), + NULL }, &cpu_index_tuple_cost, DEFAULT_CPU_INDEX_TUPLE_COST, 0, DBL_MAX, NULL, NULL }, { {"cpu_operator_cost", PGC_USERSET, QUERY_TUNING_COST, - gettext_noop("Sets the planner's estimate of processing cost of each operator in WHERE."), - gettext_noop("This is measured as a fraction of the cost of a sequential " - "page fetch.") + gettext_noop("Sets the planner's estimate of the cost of " + "processing each operator or function call."), + NULL }, &cpu_operator_cost, DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL }, { + {"effective_cache_size", PGC_USERSET, QUERY_TUNING_COST, + gettext_noop("Sets the planner's assumption about size of the disk cache."), + gettext_noop("That is, the portion of the kernel's disk cache that " + "will be used for PostgreSQL data files. This is measured in disk " + "pages, which are normally 8 kB each.") + }, + &effective_cache_size, + DEFAULT_EFFECTIVE_CACHE_SIZE, 1, DBL_MAX, NULL, NULL + }, + + { {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO, gettext_noop("GEQO: selective pressure within the population."), NULL diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index d7f32256d11..0499223d110 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -175,12 +175,12 @@ # - Planner Cost Constants - +#seq_page_cost = 1.0 # measured on an arbitrary scale +#random_page_cost = 4.0 # same scale as above +#cpu_tuple_cost = 0.01 # same scale as above +#cpu_index_tuple_cost = 0.001 # same scale as above +#cpu_operator_cost = 0.0025 # same scale as above #effective_cache_size = 1000 # typically 8KB each -#random_page_cost = 4 # units are one sequential page fetch - # cost -#cpu_tuple_cost = 0.01 # (same) -#cpu_index_tuple_cost = 0.001 # (same) -#cpu_operator_cost = 0.0025 # (same) # - Genetic Query Optimizer - |