Data Processing Data Storage and Retrieval 3

Question 1

What is a full-text search index?

Accepted Answer

An index that enables searching for words within text fields across large document collections

Answer

A full-text search index tokenizes and indexes the words within text fields, enabling fast keyword searches across large volumes of text content.

Question 2

What is data replication in database systems?

Accepted Answer

Maintaining copies of the same data on multiple servers or locations for availability and fault tolerance

Answer

Data replication copies and maintains synchronized data across multiple servers or geographic locations to ensure availability, fault tolerance, and load distribution.

Question 3

What is the CAP theorem in distributed systems?

Accepted Answer

A distributed system can guarantee at most two of three properties: Consistency, Availability, and Partition tolerance

Answer

The CAP theorem states that a distributed data system cannot simultaneously guarantee consistency, availability, and partition tolerance — only two can be fully achieved at once.

Question 4

What is a materialized view in database storage?

Accepted Answer

A precomputed and physically stored result of a query that is refreshed periodically

Answer

A materialized view stores the precomputed result of a query as a physical table that can be queried directly, improving performance at the cost of storage and periodic refresh overhead.

Question 5

What is write-ahead logging (WAL) in databases?

Accepted Answer

A technique where changes are first written to a log before being applied to the database, ensuring durability

Answer

Write-ahead logging records every change to a log file before applying it to the actual data, ensuring that committed transactions can be recovered after a crash.

Data Processing Practice Test

Data Processing Practice Test

Data Processing Data Storage and Retrieval 3