An efficient database query optimizer for large complex join queries

New interest in query capabilities for on-line analytical processing (OLAP) and large data warehouses created new challenge to current optimizers in commercial relational database, which have often proved inadequate to the needs of these application areas. Query optimizers were already among the largest and most complex modules of database systems, and they have proven difficult to modify and extend to accommodate these areas.

Columbia query optimizer framework provided an effective test environment for aggregation transforms on decision-support queries. This is the source code for the Columbia query optimizer that I wrote during my Master thesis research in Portland State University.

Columbia Query Optimizer Project page: http://web.cecs.pdx.edu/~len/Columbia/