ADBMS_Quiz_2_Section_B

What is the main purpose of query parsing?

• Generate output

• Optimize query

• Check syntax and translate SQL to internal format

• Evaluate results

Which of the following is an internal representation used in query processing?

• SQL

• Relational Schema

• Extended Relational Algebra

• Procedural Language

In the query SELECT balance FROM account WHERE balance < 2500;, which relational algebra operation represents filtering?
A)
B)
C)
D)

• Π (pi)

• σ (sigma)

• ∪ (union)

• × (cross product)

What is a major disadvantage of centralized databases?

• Single point of failure

• Difficult to back up

• Requires more developers

• Lower performance

Which of the following best describes a distributed database?

• Runs on a single server

• Uses a central system for storage

• Cannot operate offline

• Stores data across multiple locations

Which of the following improves fault tolerance?

• Centralization

• Replication

• Compression

• Caching

When should vertical fragmentation be used?

• When dividing data by location

• When minimizing CPU time

• When separating attributes used by different apps

• When reducing server load

Why is concurrency control more difficult with replication?

• Same data updated at multiple sites

• More tables created

• Joins are expensive

• Many locks needed

Which operation would best resolve conflicts in a replicated distributed system?

• Timestamp-based conflict resolution

• Load balancing

• Trigger-based rollback

• Aggregation

A DBMS that can handle multiple data models and systems is:

• Centralized

• Heterogeneous distributed

• Homogeneous

• File-based