Database Concepts for the Systems Analyst
Records
- When a computer program ‘reads’ a record from a database, it actually retrieves a group or block of records at a time.
- This approach minimizes the number of actual disk accesses.
- A blocking factor is the number of logical records included in a single read or write operation (from the computer’s perspective). A block is sometimes called a physical record.
- Today, the blocking factor is usually determined and optimized by the chosen database technology, but a qualified database expert may be allowed to fine tune that blocking factor for performance.