C100DBA Sharding Practice Question
Which TWO of the following are primary benefits of implementing sharding in a MongoDB environment?
⚠ Common exam trap
Candidates often incorrectly select 'automatic data encryption' or 'high availability' as primary benefits of sharding, failing to distinguish between core sharding features and replica set capabilities.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Increased storage capacity by spreading data across multiple shards.
Sharding provides horizontal scaling, allowing a database to handle loads beyond the capacity of a single server. By distributing data across multiple machines, it increases both the total storage capacity and the aggregate I/O throughput. This architectural pattern is essential for large-scale applications where vertical scaling becomes cost-prohibitive or physically impossible due to hardware limitations on a single node.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Increased storage capacity by spreading data across multiple shards.
Why this is correct
Each shard in a cluster stores a subset of the total dataset. By adding more shards, the cluster can manage significantly larger volumes of data than any individual replica set could support. This allows for near-infinite growth of the database footprint without requiring massive individual server upgrades.
- ✗
Automatic failover and high availability for the entire cluster.
Why it's wrong here
While each shard is typically a replica set that provides high availability, sharding itself is focused on horizontal scaling and data distribution. High availability is a property of the replica set architecture used within the shards, rather than a benefit introduced specifically by the sharding layer of the cluster.
- ✓
Improved read and write throughput through parallel processing.
Why this is correct
Sharding allows operations to be distributed across multiple servers. When queries include the shard key, the mongos can route them to specific shards, enabling parallel processing of requests. This prevents any single machine from becoming a bottleneck for the entire application traffic, significantly boosting overall performance.
- ✗
Simplified backup and recovery processes for large datasets.
Why it's wrong here
Sharding actually increases the complexity of backup and recovery operations. Backing up a sharded cluster requires coordinating snapshots across all shards and config servers to ensure point-in-time consistency. This is generally more difficult and resource-intensive than managing a single standalone replica set or a single node.
- ✗
Reduced latency for all queries regardless of the shard key used.
Why it's wrong here
Sharding only reduces latency for queries that can be targeted to specific shards using the shard key. Queries that do not include the shard key must be broadcast to all shards, which often results in higher latency and increased resource consumption compared to a non-sharded environment.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official MongoDB exam blueprint
This C100DBA practice question is part of Courseiva's free MongoDB certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the C100DBA exam.