Invention Grant
- Patent Title: Dynamically adjust duplicate skipping method for increased performance
-
Application No.: US14170316Application Date: 2014-01-31
-
Publication No.: US09892158B2Publication Date: 2018-02-13
- Inventor: Terence P. Purcell , Thomas A. Beavin , Li Xia , Michael R. Shadduck , Paramesh S. Desai , Qianyang Yu
- Applicant: International Business Machines Corporation
- Applicant Address: US NY Armonk
- Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
- Current Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
- Current Assignee Address: US NY Armonk
- Agency: Patterson + Sheridan, LLP
- Main IPC: G06F17/30
- IPC: G06F17/30

Abstract:
Embodiments presented herein provide techniques for setting different methods of skipping duplicate values when executing a query statement in a relational database. A distance between a two distinct keys in an index, a current index key and a next distinct index key, are estimated. Based on the estimated distance, an appropriate duplicate-skipping method is determined. If the proximity between the distinct keys is relatively far apart (e.g., the keys reside in index pages that are at least an index page apart), then a “big skip” method is performed. Otherwise, if the proximity between the distinct keys is relatively near (e.g., the keys reside in the same index page), then a “little skip” method is performed.
Public/Granted literature
- US20150220595A1 DYNAMICALLY ADJUST DUPLICATE SKIPPING METHOD FOR INCREASED PERFORMANCE Public/Granted day:2015-08-06
Information query