DATAFLOW OPTIMIZATION FOR EXTRACTIONS FROM A DATA REPOSITORY

摘要

Dataflow optimization is described for extractions from a data depository. In one example an object-relationship graph of a data extraction definition is traversed in a first pass. The object-relationship graph has a node for each object. The steps from each node of the graph in the first pass is determined. It is determined if any of the determined steps are repeated. A single instance of each repeated step is placed before other steps in a query plan. Data is then extracted in a second pass from the object-oriented database system according to the object-relationship graph by performing the repeated steps first and then reusing the repeated steps in other determined steps.

主权项

1. A database system-implemented method comprising:
traversing an object-relationship graph of a data extraction definition in a first pass, the object-relationship graph having a node for each object; determining steps from each node of the graph in the first pass; determining if any of the determined steps are repeated; placing a single instance of each repeated step before other steps in a query plan; extracting data in a second pass from an object-oriented database system according to the object-relationship graph by performing the repeated steps first and then reusing the repeated steps in other determined steps.