Is there any performance gain or loss from stuffing two columns into one index, e.x.
CREATE INDEX `myindex1` ON `nodes` (`n_lat`, `n_lon`); compared to: CREATE INDEX `myindex2` ON `nodes` (`n_lat`); CREATE INDEX `myindex3` ON `nodes` (`n_lon`); when doing a query like this: SELECT * FROM nodes WHERE n_lat >= 51 AND n_lon >= -1 AND n_lat <= 53 AND n_lon <= 1; Will SQLite do more or less work on either? Or are they virtually equivalent? I have been trying to get R*-Trees working and I have had limited success with my roads database but nodes do not want to cooperate, getting Constraint Errors all around. Also, is a UNIQUE index faster to read than a non-UNIQUE index in any way? Unfortunately, I am struggling to test this myself, as my only datasets available are 1-2 GB (XML) and these take about 2-3 hours to load into SQLite using a short Python program. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
