GATE | CSE 2023 | Question 65

Consider a database of fixed-length records, stored as an ordered file.  The database has  25,000  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

Suppose the block size of the file system is 1024 bytes, and a pointer to a block occupies 5 bytes. The system uses binary search on the index file to search for a record with a given key. You may assume that a binary search on an index file of b blocks takes log b block accesses in the worst case.

Given a key, the number of block accesses required to identify the block in the data file that may contain a record with the key, in the worst case, is ____________

(A)

(B)

(C)

(D)