2. The computer-executed method of claim 1 further comprising: prior to forming the fused path expression from the two or more path expressions, identifying the two or more path expressions by: identifying a set of one or more operators from the particular query; wherein each operator of the set of one or more operators is associated with a particular operator from the particular query; and identifying the two or more path expressions as path expressions that are each associated with at least one operator of the set of one or more operators.
2. The computer-executed method of claim 1 further comprising: prior to forming the fused path expression from the two or more path expressions, identifying the two or more path expressions by: identifying a set of one or more operators from the particular query; wherein each operator of the set of one or more operators is associated with a particular operator from the particular query; and identifying the two or more path expressions as path expressions that are each associated with at least one operator of the set of one or more operators. 4. The computer-executed method of claim 2 , further comprising: prior to the step of determining that the fused path expression matches an index definition path expression for the particular structured index: identifying one or more index tables that contain information referred to by each fused path expression associated with two or more operators from the particular query; determining whether the one or more index tables includes only a single index table; in response to determining that the one or more index tables includes only a single index table, writing a particular single subquery on the single index table to evaluate each operator of the two or more operators; and wherein the step of rewriting the particular query to include a subquery on the particular structured index comprises rewriting the particular query to include the particular single subquery.