Design of indexes in a relational database management system is based on a workload analysis of all requests in a system. Each request is assigned a value of importance, and requests are broken into expressions, contexts and columns to facilitate identification of candidate indexes. Candidate indexes are compared to existing indexes to determine whether the existing indexes can be reused or modified. Candidate indexes are classified as hashed or sorted. Based on the index design, record placement is selected to be hashed, sorted or by default. Related indexes and tables are clustered and the clusters are sized to fit file areas. Cache buffers are also defined.