Overal comment.. Try reading hrough these old threads most of your
problem is the same issue:
http://article.gmane.org/gmane.comp.db.postgresql.performance/22395/match=gin
http://thread.gmane.org/gmane.comp.db.postgresql.performance/22331/focus=22434
Karl,
estimation for gin indexes currently is very-very bad, so I don't surprise
your result. We'll discuss on pgcon our new ginconstetimate function,
which could improve planner. Can you provide us dump of your db (with
relevant columns) and test queries, so we could check our new patch.
Oleg
