Creating a physical database design can be a complex and difficult task. This chapter presents a four-phase methodology for selecting primary search keys and the corresponding files structure for each table, determining how to support join operations, selecting secondary search keys and appropriate supporting access methods, and identifying and supporting composite search keys and structures. Creating the initial physical database design is an important stage in the database lifecycle. The database administrator (DBA) determines the physical data structures for representing data so that the data base management system efficiently processes queries and transactions in the workload. A data page is a unit of data that is transferred between disks and main memory and usually contains several database records. DBAs design physical databases so the number of data pages being transferred is minimized for frequently performed queries. DBAs design physical databases to efficiently access database tables using search keys. Some tables have multiple search keys.