On Jan 7, 2010, at 8:18 AM, Tim Romano wrote: > I don't claim any SQLite expertise, but indexes on values like > True/False, Male/Female -- i.e. where there are only a couple or a few > different values possible in the column -- are normally to be > avoided > because low-cardinality indexes tend to be inefficient. What is the > advice of the SQLite gurus in this respect?
This is good advice. If you run ANALYZE, SQLite will figure out that the index is mostly useless and will hardly ever use it. (There are some obscure queries for which such an index would be useful, but they are the exception rather than the rule.) On the other hand, SQLite still has to maintain the index on INSERT, UPDATE, and DELETE operations which will slow those operations down. D. Richard Hipp d...@hwaci.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
