Eladio Rocha
Quiz by , created 19 days ago

Test your knowledge of modern scalable databases, including sharding, NoSQL systems like MongoDB and Cassandra, and the trade-offs between normalized and denormalized data.

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Eladio Rocha
Created by Eladio Rocha 19 days ago
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Modern Scalable Databases

Modern Scalable Databases

Question 1 of 13

1

What is the primary purpose of a router in a scalable database design?

Select one of the following:

  • To perform joins between shards.

  • To route client requests to the appropriate shard.

  • To store backup configurations for shards.

  • To hash keys for partitioning data.

Explanation

Question 2 of 13

1

What is a "shard" in the context of databases?

Select one of the following:

  • A method of encrypting sensitive data.

  • A backup server in a replica set.

  • A horizontal partition of a database.

  • A tool for monitoring database traffic.

Explanation

Question 3 of 13

1

What is a major advantage of sharding in database systems?

Select one of the following:

  • It eliminates the need for backups.

  • It increases both scalability and redundancy.

  • It simplifies complex SQL queries.

  • It reduces the need for a router.

Explanation

Question 4 of 13

1

What is a replica set in MongoDB?

Select one of the following:

  • A set of configuration servers.

  • A collection of shards distributed across regions.

  • A primary server and its associated secondary servers for redundancy.

  • A group of shards that handle write-heavy traffic.

Explanation

Question 5 of 13

1

How does MongoDB ensure high availability when a primary server fails?

Select one of the following:

  • Traffic is rerouted to the config server.

  • Secondary servers automatically elect a new primary.

  • The router assigns new shards dynamically.

  • The primary server is rebooted automatically.

Explanation

Question 6 of 13

1

What does "eventual consistency" mean in the context of Cassandra?

Select one of the following:

  • Data is always immediately consistent across all nodes.

  • Data might take time to propagate across nodes, leading to temporary inconsistencies.

  • Data must be manually synchronized across nodes.

  • Consistency is not guaranteed due to system failures.

Explanation

Question 7 of 13

1

What is the "celebrity problem" in sharded databases?

Select one of the following:

  • High traffic on specific shards causes uneven load distribution.

  • Celebrities’ data is stored differently for security reasons.

  • All shards are overloaded with high read and write requests.

  • Certain shards fail to replicate data efficiently.

Explanation

Question 8 of 13

1

What is re-sharding, and why is it challenging?

Select one of the following:

  • Redistributing data when adding or removing shards, which requires fault-tolerant methods.

  • Creating backups for new shards added to the system.

  • Replicating data across all shards during traffic spikes.

  • Distributing write-heavy traffic across existing shards.

Explanation

Question 9 of 13

1

What is a key advantage of using a normalized database schema?

Select one of the following:

  • It minimizes storage space and simplifies updates.

  • It allows faster reads with fewer database hits.

  • It duplicates data for high performance.

  • It eliminates the need for joins between tables.

Explanation

Question 10 of 13

1

Why might denormalized data be preferred in a NoSQL database?

Select one of the following:

  • It reduces redundancy and improves update efficiency..

  • It allows for single-query retrieval of all necessary data.

  • It enforces strict schema rules.

  • It is easier to scale horizontally.

Explanation

Question 11 of 13

1

What should you prioritize when designing a horizontally scalable database?

Select one of the following:

  • Using as many joins as possible for efficiency.

  • Designing around simple key-value lookups to avoid joins.

  • Avoiding hash functions for data distribution.

  • Relying heavily on a single primary server for consistency.

Explanation

Question 12 of 13

1

Which database systems are examples of NoSQL?

Select one of the following:

  • PostgreSQL and MySQL.

  • MongoDB, Cassandra, and DynamoDB.

  • Oracle and SQLite.

  • Redis and HBase and SQLite

Explanation

Question 13 of 13

1

In what scenarios might you choose to use normalized data over denormalized data in a NoSQL database?

Select one of the following:

  • When updates are frequent and space efficiency is important.

  • When scaling horizontally is a top priority.

  • When high traffic requires fewer database hits.

  • When you need to perform complex joins efficiently.

Explanation

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