Questions where students often pick the tempting wrong answer — make sure you know the right one:
What is the purpose of database normalisation?✗ To make the database run faster.✓ To reduce redundancy and avoid update anomalies.
What does an INNER JOIN return?✗ All rows from both tables combined.✓ Only rows with matching values in both tables.
Is the DBMS the same thing as the database?✗ Yes - DBMS is simply the technical name for the data itself.✓ No - the database is the organised collection of data; the DBMS is the software layer that manages access to it, like MySQL or Oracle.
Can you safely delete a customer record while orders still reference it?✗ Yes - deleting a parent record has no effect on other tables.✓ No - referential integrity forbids leaving orphaned foreign keys; the DBMS will block the deletion or cascade it according to defined rules.
Is data redundancy good because it acts as a backup?✗ Yes - storing each fact several times protects against data loss.✓ No - uncontrolled duplication inside a database causes inconsistencies when copies diverge; backups are deliberate, separate, managed copies of the whole database.
Practise Databases & SQL — free games
Test yourself with these quick revision games for this topic:
