2012-03-24Searching for Ranges

Inequality operators such as <, > and between can use indexes just like the equals operator explained above. Even a LIKE filter can—under certain circumstances—use an index just like range conditions do.

Using these operations limits the choice of the column order in multi-column indexes. This limitation can even rule out all optimal indexing options—there are queries where you simply cannot define a “correct” column order at all.