Database indexes

A system for database indexing, a database index comprises at least one index include, the system comprising:

• a computer system comprising one or more computer processors, one or more computer-readable storage media, and program instructions stored on one or more of the computer-readable storage media for execution by at least one of the one or more processors, the computer system comprising:
• an obtaining unit configured to obtain a number of executions, the number of executions of each of a plurality of Structured Query Language (SQL) statements within a certain time period, respectively, wherein the plurality of SQL statements use the database index;
• a hit frequency calculating unit configured to, for the at least one index:
• calculate a number of hits of the index include according to the number of executions of each of the plurality of SQL statements;
• obtain a length of the index include;
• calculate a hit frequency of the index include by using the number of hits and the length of the index include, wherein:
• the hit frequency equals the number of hits divided by the length.

A computer program product for database indexing, a database index including at least one index include, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions executable by a computer to cause the computer to perform a method, comprising:

• obtaining the number of executions of each of a plurality of Structured Query Language (SQL) statements within a certain time period, respectively, wherein the plurality of SQL statements use the database index;
• for each of the at least one index include:
• calculating a number of hits of the index include according to the number of executions of each of the plurality of SQL statements;
• obtaining a length of the index include;
• calculating a hit frequency of the index include by using the number of hits and the length of the index include, wherein:
• the hit frequency equals the number of hits divided by the length.