Index selection for XML database systems

摘要

A method, computer-implemented system, and computer program product for creating indexes over XML data managed by a database system are provided. The method, computer-implemented system, and computer program product provide for receiving a workload for the XML data, the workload including one or more database statements, utilizing an optimizer of the database system to enumerate a set of one or more path expressions by creating a virtual universal index based on the workload received and matching a path expression to the virtual universal index, and recommending one or more path expressions from the set of one or more candidate path expressions to create the indexes over the XML data.

主权项

1. A method for creating indexes over XML data managed by a database system, the method comprising:
receiving a workload for the XML data, the workload including one or more database statements; utilizing an optimizer of the database system to enumerate a set of one or more candidate path expressions by creating virtual universal indexes for an element, an attribute, and a data type in the XML data and matching a path expression to one of the virtual universal indexes; and recommending one or more path expressions from the set of one or more candidate path expressions to create the indexes over the XML data based on a system constraint, an estimated benefit associated with each candidate path expression, and an estimated size of an index to be created using each candidate path expression.