International Business Machines Corporation
Efficient indexing of columns with inappropriate data types in relational databases

Abstract:

A computer-implemented method, a computer program product, and a computer system for detecting an inappropriate data type of a column in a database and building a physical access path over a correct data type. The computer system detects in a table a candidate column with a first data type that has a mismatching type definition, using database usage statistics. The computer system determines whether it is possible to build an additional index as an access path over values with a second data type. The computer system, in response to determining that it is possible to build the additional index, converts values in the candidate column to the values with the second data type. The computer system builds the additional index over the values with the second data type in the table. The computer system generates a query plan operator for the additional index.