Consider a database of fixed$-$length records, stored as an ordered file. The database has $25000$

records, with each record being $100$

bytes, of which the primary key occupies $15$

bytes. The data file is block$-$aligned in that each data record is fully contained within a block. The database is indexed by a primary index file, which is also stored as a block$-$aligned ordered file. The figure below depicts this indexing scheme.