5. File Access Mode

Understand how systems read and write records using different file access methods.

Data is written sequentially.

Access speed depends on the location of the target data.

Example: magnetic tape.

Data can be written to any position.

Each storage position has a unique address.

Data can be accessed directly without starting from the beginning.

Examples: hard disk, USB flash drive, and floppy disk.

File: StudentRecords.txt

Name	Class	Class No.	Grade
John	4A	1	A
Mary	4A	2	C
Bob	4A	3	B
Tom	4B	4	D
Alice	4B	5	F

Process:

Time: ~0 reads

Direct access with index lookup

Addr	Name	Class	Class No.	Grade
0	John	4A	1	A
100	Mary	4A	2	C
200	Bob	4A	3	B
300	Tom	4B	4	D
400	Alice	4B	5	F

Process:

Time: ~0 read