Tom, This is a realistic case: everyone have Python and Java skills, but PostGis and Haskell and Closure are rare. If we are looking for a person that has all the skills required for a task (array[1, 15]), that is "skills <@ array[1, 15] " and not the opposite, right? Also can you explain why " entries for "0" and "1" swamp everything else so that the planner doesn't know that eg "15" is really rare. " I thought that if a value is not found in the histogram, than clearly that value is rare, correct? What am I missing here? I hear what you are saying about "don't keep both extremely common and extremely rare entries in the same array", but I cannot predict the future, so I do not know which values are going to be common next year, or two years later. So I think it would be very difficult to follow this advice. What do you think? -- View this message in context: http://postgresql.nabble.com/Why-is-GIN-index-slowing-down-my-query-tp5836319p5836323.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance