o.permazen.index"><code>Index2</code></a><code>&lt;String, Float, User&gt;</code>; a composite index on
 three fields of type <code>X</code>, <code>Y</code>, and <code>Z</code> by a <a href="Index3.html" title="interface in io.permazen.index"><code>Index3</code></a><code>&lt;X, Y, Z, User&gt;</code>, etc.

 <p>
 A composite index may be viewed as a set of tuples of indexed and target values, or as various mappings from one
 or more indexed field values to subsequent values.

 <p>
 A composite index may alwa