Log Message:
-----------
Save another little bit of planner overhead on simple queries, by having
clauselist_selectivity skip some analysis that's useless when there's only
one clause in the given list. Actually this can win even for not-so-simple
queries, because we also apply clauselist_selectivity to sublists such as the
quals matching an index; which are likely to have only a single entry even
when the total query is quite complicated.
Modified Files:
--------------
pgsql/src/backend/optimizer/path:
clausesel.c (r1.87 -> r1.88)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/clausesel.c?r1=1.87&r2=1.88)