The Catalog Archive Server is indexed to allow efficient queries on quantities commonly used in astronomical research (position, and magnitudes in our five filters). It also allows algebraic combinations of these quantities to be used in the queries. We have written a unique and powerful database server which allows users to make sophisticated queries efficiently. The general strategy of compiling a large astronomical database is described in szalay01, and our method of dividing the celestial sphere into a hierarchical triangular mesh, which enables efficient access based on position, is described in kunszt00. The database server software is described in thakar00.