ITPEC FE Subject A April 2025 Question 22

Source exam: ITPEC FE Subject A April 2025Topic: Databases

ITPEC FE Subject A April 2025 — Question 22 of 60

Lock Granularity — the size of the data unit that a lock covers.

  • Large granularity (e.g., table-level lock): fewer locks to manage, but other transactions must wait longer → waiting time increases, throughput declines
  • Small granularity (e.g., row-level lock): more locks to manage (higher overhead), but better concurrency → more parallel transactions

Why (c):
- Large granularity locks a big chunk of data for updates

- Other transactions that need any part of that data must wait

- Result: increased waiting time + decreased throughput

Why not others:
- (a) Large granularity decreases concurrency, not increases it

- (b) Large granularity locks more data, so other transactions' data is disturbed

- (d) Large granularity means fewer locks (one lock covers many items), not more

Key rule: Large granularity = fewer locks + less concurrency. Small granularity = more locks + more concurrency.

AI-generated — may contain errors

The original exam layout is preserved in the image so diagrams, formulas, tables, and code remain accurate.

This question comes from an official ITPEC past paper. ITPEC Practice is an independent study tool and is not affiliated with ITPEC. See the official FE past-paper collection or Report an issue.