Implementing Aggregation Combination Using Aggregate Depth Lists and Cube Aggregation Conversion to Rollup Aggregation for Optimizing Query Processing

An apparatus for implementing aggregation combination using aggregate depth lists for optimizing database query processing comprising:

• a processor;
• a database management system including a query optimizer;
• said query optimizer generating an access plan utilizing single rollup sets and rollup depth lists;
• said query optimizer combining multiple grouping sets into single rollup sets;
• and assigning rollup depth lists defining the levels of grouping to be performed;
• and
• a database execution engine executing a database query with said access plan.

A computer-readable storage medium encoded with a computer program product for implementing aggregation combination using aggregate depth lists for optimizing database query processing in a computer system, said computer-readable storage medium encoded with said computer program product including instructions executed by the computer system to cause the computer system to perform the steps of:

• identifying grouping sets and combining multiple grouping sets into single rollup sets;
• and
• assigning rollup depth lists defining the levels of grouping to be performed;
• generating an access plan utilizing said single rollup sets and said rollup depth lists;
• and
• executing a database query with said access plan.