An Efficient Algorithm for Minimizing Tree Pattern Queries in the Presence of Integrity Constrains

Tree pattern is the natural model to query tree-structured data such as XML and LDAP-style network directories. The efficiency of finding the result of a query on a given input database depends on the size of the query. So, it's important to minimize the query before attempting to compute the result of the query. Required-child, required-descendant and subtype integrity constrains all prevail in tree-structured databases. An O(n2) algorithm called MinTPQ for minimizing tree pattern queries on the tree-structured database is introduced in the presence of the three kinds of integrity constraints; n is the number of the nodes of the tree pattern queries. The algorithm is based on the concept of extended simulation. Analytical result shows the effectiveness of the tree pattern minimization technique.