§1 Access methods
For fixed-length records numbered from 1, the byte offset of record n is (n − 1) × record length.
| Method | How | Best for |
|---|---|---|
| Sequential | Read records in order from the start | Batch processing every record |
| Direct (random) | Jump to a computed position | Fixed-length records, quick lookup |
| Indexed sequential | Sorted records plus an index | Both batch runs and lookups |
§2 File operations
! Common traps
- Opening an existing data file in write mode and erasing it.
Coverage source: 2023 ICT Proficiency Certification Examination FAQs (file dated 14 Feb 2023) (third-party copy)