G - Physics – 06 – F
Patent
G - Physics
06
F
G06F 17/00 (2006.01) G06F 7/00 (2006.01) G06F 17/30 (2006.01)
Patent
CA 2390350
A technique is provided for incrementally maintaining column cardinality estimates in database management systems. The system catalog table containing a cardinality estimate for a column is extended to include an appropriate data structure. A modified linear counting technique is used in a first embodiment of a method for column cardinality estimation. Moreover, a modified logarithmic counting technique is used in a second, preferred embodiment of a column cardinality estimation method to reduce storage requirements for the data structure. The cardinality estimate is produced by an initial scan of the data but is then further maintained without requiring a full scan of the data. Data changes are reflected incrementally in modifications to the initial cardinality estimate, keeping the cardinality statistics more current with respect to the database condition. The technique of the invention typically provides a capability for a database management system to produce more efficient search plans providing more effective responses to user queries through the use of improved cardinality statistics.
Haas Peter Jay
Rjaibi Walid
Ibm Canada Limited - Ibm Canada Limitee
Rosen Arnold
LandOfFree
Incremental cardinality estimation for a set of data values does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Incremental cardinality estimation for a set of data values, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Incremental cardinality estimation for a set of data values will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1648680