Parallel query processing for complex objects

The authors investigate a direct storage scheme for complex objects called FIHSM (Fully Inverted Hierarchical Storage Model) and propose a novel parallel-query-processing strategy (QPS) for it. The QPS has four phases (select, pivot, value materialize and compose). With a declustered placement strategy, each of these phases provides for both inter and intra-operation parallelism. Furthermore, partial results of one phase could be pipelined to the subsequent phase. The proposed four-phase structured algorithm is based on heuristics and thus avoids the prohibitive exhaustive searches which are needed for optimizing query executions in parallel environments