From 9f5f2124754ccd605671bfe952c220b46a0e730b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 25 Jan 2003 23:10:30 +0000 Subject: Allow the planner to collapse explicit inner JOINs together, rather than necessarily following the JOIN syntax to develop the query plan. The old behavior is still available by setting GUC variable JOIN_COLLAPSE_LIMIT to 1. Also create a GUC variable FROM_COLLAPSE_LIMIT to control the similar decision about when to collapse sub-SELECT lists into their parent lists. (This behavior existed already, but the limit was always GEQO_THRESHOLD/2; now it's separately adjustable.) --- src/backend/utils/misc/postgresql.conf.sample | 3 +++ 1 file changed, 3 insertions(+) (limited to 'src/backend/utils/misc/postgresql.conf.sample') diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index 41750b9e229..515eec9acae 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -94,6 +94,9 @@ #cpu_index_tuple_cost = 0.001 # (same) #cpu_operator_cost = 0.0025 # (same) +#from_collapse_limit = 8 +#join_collapse_limit = 8 # 1 disables collapsing of explicit JOINs + #default_statistics_target = 10 # range 1-1000 # -- cgit v1.2.3