Techniques are disclosed for optimizing queries to hierarchically structured data. For example, a method for processing a query directed to data having a hierarchical structure with a plurality of data nodes comprises the following steps. One or more structural attributes describing the hierarchical structure of the data are identified. The query is partitioned into two or more query partitions using at least one of the one or more identified structural attributes. A parallel execution plan is determined for the query by splitting into components one or more of: the query into at least two of the query partitions; and the hierarchical structure of the data. The split components are executed in parallel on different computer processes according to the parallel execution plan.