Determining query cost based on subquery filtering factor

Details Determining query cost based on subquery filtering factor Determining query cost based on subquery filtering factor

2007-06-19

2007-06-19

Rones, Charles (Department: 2164)

Data processing: database and file management or data structures

Database design

Data structure types

C707S793000, C707S793000, C707S793000

Reexamination Certificate

active

10900788

ABSTRACT:
Techniques are provided for determining query cost for a query that include an outer query and at least a first subquery. The techniques include determining a filtering factor for the first subquery based on a first cardinality and a second cardinality. The first cardinality is determined based on a first set of query blocks in the query. The second cardinality is determined based on a second set of query blocks. The first set of query blocks includes the outer query and zero or more subqueries from the query and does not include the first subquery. The second set of query blocks includes all the query blocks in the first set of query blocks and, in addition, the first subquery. The techniques also include determining a cost for the query based, at least, on the filtering factor for the first subquery.

REFERENCES:
patent: 5822748 (1998-10-01), Cohen et al.
patent: 2005/0283471 (2005-12-01), Ahmed
patent: 2006/0026133 (2006-02-01), Ahmed
George Lumpkin, Hakan Jakobsson, “Query Optimization in Oracle 9i”, Oracle Corporation, Oracle White Paper, Feb. 2002, pp. 1-30.
Hamid Pirahesh, Joseph M. Hellerstein, Waqar Hasan, “Extensible/Rule Base Query Rewrite Optimization in Starbust”, IBM Almaden Research Center, Jun. 1992. pp. 1-10.
Umeshwar Dayal, “Of Nests and Trees: A Unified Approach to Processing Queries That Contain Nested Subqueries, Aggregates and Quantifiers”, Proceedings of the 13thVLDB Conference, Brighton 1987, pp. 197-208.
P. Griffiths Selinger, M.M. Astrahan, D.D. Chamberlin, R.A. Lorie, T.G. Price, “Access Path Selection in a Relational Database Management System”, Proceedings of the 1979 ACM SIGMOD International Conference on the Management of Data, 1979, pp. 23-34.

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