If you're using MyISAM and you don't care about diskspace then you can use an R-tree index to search any two inequalities. For example, an R-tree index can be u

If you're using MyISAM and you don't care about diskspace then you can use an R-tree index to search any two inequalities. For example, an R-tree index can be used for queries of the form A>10 AND A<100 AND B>5. Also note that R-tree indexes can be appended to my previously suggested indexes. So, an index of the form (C,D,E,R) would efficiently locate rows for a query of the form C=3 AND D=4 AND E=5 AND A>10 AND A<100 AND B>5