* Igor Tandetnik: > L B <brasiorid...@yahoo.com> wrote: >> The explanation you made is only valid for sqlite or >> for SQL in general? > > For SQL in general.
True, but there are some database engines that support skip-index scans, so if there are only few different values of X, say x_1, ... x_k, you've got an index on (X, Y) and want to find all y, the query is executed as lookups for (x_1, y), ..., (x_k, y). (Obviously, this is only beneficial if k is not too big.) _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
