Nelson Mullins Riley & Scarborough LLP
Method and apparatus for optimizing access path in database
Apparatuses and methods for optimizing access path are provided. Execution of a query statement is sampled to obtain the information about a plurality of executing instances, the information about each executing instance comprises the literal value of the query statement in the instance and the filter factor corresponding to the literal value. The plurality of instances are grouped into a plurality of groups based on the filter factors corresponding to the literal values. The average filter factor of each group and the occurrence frequency of the group are obtained. The candidate access path created for the average filter factor of each group is accordingly obtained, and by taking the occurrence frequencies as weights, the weighted execution cost of each candidate access path is calculated for each group. The candidate access path with the minimum sum of the weighted execution costs for all groups is determined as the optimal access path.
INTERNATIONAL BUSINESS MACHINES CORPORATION
G G
G06F G06F
inventional inventional
Patrick D. Jing You-Chin Ke W. Xiang
Bossman Zhou Fuh Wei Zhou