A new schema which models the usage of the logical access paths of the database is proposed. The schema models all database activities (i.e., retrievals and updates), and integrates their logical access paths by recognizing common subpaths and increasing the "weight" of the shared subpaths. The logical access path schema provides a comprehensive picture of the logical access paths, and the cumulative usage of the shared subpaths and/or intermediate results. The schema serves a dual purpose. Firstly, it is used as a model of the access requirements during the database design, and secondly, as the basis for optimization during the operation of the database.