Matthew Wakeling <matthew@xxxxxxxxxxx> writes: > When I wrap the fields in the constraints in a LOWER() function, the > planner stops looking at the statistics and makes a wild guess, even > though it is very obvious from just looking what the result should be. Well, in general the planner can't assume anything about the statistics of a function result, since it doesn't know how the function behaves. In this case, however, you evidently have an index on lower(distance) which should have caused ANALYZE to gather stats on the values of that functional expression. It looks like there might be something wrong there --- can you look into pg_stats and see if there is such an entry and if it looks sane? > Also, why does the BitmapAnd say zero actual rows? There isn't any reasonably-inexpensive way for EXPLAIN ANALYZE to determine how many rows are represented by a bitmap result, so it doesn't try. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
