Database Management

36. Which type of join returns all the rows from both tables, filling in NULL values for non-matching rows?
A) LEFT JOIN
B) RIGHT JOIN
C) INNER JOIN
D) FULL JOIN

37. In a database, a check constraint is used to:
A) Enforce a relationship between two tables
B) Define the data types for attributes
C) Ensure that data meets specific criteria
D) Speed up data retrieval

38. Which SQL command is used to change the data in a database table?
A) UPDATE
B) MODIFY
C) ALTER
D) CHANGE

39. The process of creating a copy of a database to protect against data loss is called:
A) Cloning
B) Replication
C) Backup
D) Sharding

40. Which type of database model uses a graph-like structure to represent data relationships?
A) Hierarchical
B) Network
C) Relational
D) Graph