From db147b348345288c7b47f9527fc107a9bb063ad7 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 2 May 2008 21:26:10 +0000 Subject: Allow the planner's estimate of the fraction of a cursor's rows that will be retrieved to be controlled through a GUC variable. Robert Hell --- src/backend/utils/misc/guc.c | 12 +++++++++++- src/backend/utils/misc/postgresql.conf.sample | 1 + 2 files changed, 12 insertions(+), 1 deletion(-) (limited to 'src/backend/utils/misc') diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 58b1a469ac..993cf971a9 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -10,7 +10,7 @@ * Written by Peter Eisentraut . * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.450 2008/05/01 19:55:40 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.451 2008/05/02 21:26:10 tgl Exp $ * *-------------------------------------------------------------------- */ @@ -1891,6 +1891,16 @@ static struct config_real ConfigureNamesReal[] = DEFAULT_CPU_OPERATOR_COST, 0, DBL_MAX, NULL, NULL }, + { + {"cursor_tuple_fraction", PGC_USERSET, QUERY_TUNING_OTHER, + gettext_noop("Sets the planner's estimate of the fraction of " + "a cursor's rows that will be retrieved."), + NULL + }, + &cursor_tuple_fraction, + DEFAULT_CURSOR_TUPLE_FRACTION, 0.0, 1.0, NULL, NULL + }, + { {"geqo_selection_bias", PGC_USERSET, QUERY_TUNING_GEQO, gettext_noop("GEQO: selective pressure within the population."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 9fb567bd62..ce78453083 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -219,6 +219,7 @@ #default_statistics_target = 10 # range 1-1000 #constraint_exclusion = off +#cursor_tuple_fraction = 0.1 # range 0.0-1.0 #from_collapse_limit = 8 #join_collapse_limit = 8 # 1 disables collapsing of explicit # JOIN clauses -- cgit v1.2.1