Approximate and exact unary inclusion dependency discovery

摘要

A method and apparatus for analyzing potential inclusion dependencies between columns of database tables is provided. A client issues a command, e.g., a SQL statement to a database server. The command is processed at the database server without the performance of a join. Result data that indicates any exact inclusion dependencies or approximate inclusion dependencies between columns of database tables identified in the command is transmitted from the database server to the client. In processing the command, values stored in columns of database tables are converting into integer representations that require fewer resources to analyze. Disclosed techniques provide for the use of an index on a single database table rather than defining an index on each database table, which can be impractical. Further, the performance of only one pass on the data is required to identify any inclusion dependencies between columns of database tables.