Hi all, in experimenting with indexes I found that if you create an index on (a, b) and then SELECT * FROM data WHERE a = 1 AND B = 2, it will use the index, great.
Advertising
However, if you write SELECT * FROM data WHERE a = 1, it won't use the index. If you write SELECT * FROM data WHERE a = 1 AND B != some_impossible_value, it does use the index. Is it not efficient to use an index, even if one of its values is not constrained? Case in point, I have an app that allows searching across 4 of parameters, and I am wondering if I could just use a single 4-valued index, searching for != impossible_val for unconstrained parameters. Surely that would be a better use of resources than indexes on all combinations? And if that is indeed the case, would it not be good that sqlite automatically checks multi-value indexes where it can't find a specific index? Wondering Wout. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
