What is the primary consideration for choosing between HDDs and SSDs for MongoDB storage?
Storage Capacity
Cost per Gigabyte
Data Redundancy
Random Read/Write Performance
During a read operation in MongoDB, if the requested data is not found in the WiredTiger cache, where is it retrieved from?
Oplog
Config Servers
Journal Files
Data Files
Which component of MongoDB's architecture is responsible for managing data access and concurrency?
Storage Engine
Query Engine
Router
Config Server
What is a key consideration for optimizing aggregation pipelines with large datasets in MongoDB?
Using JavaScript functions for complex logic
Minimizing the use of indexes
Performing joins as early as possible in the pipeline
Avoiding the $match stage for optimal performance
What is the purpose of the $lookup stage in the MongoDB aggregation pipeline?
Updating documents
Filtering documents
Joining documents from different collections
Sorting documents
What is a common reason for slow query performance despite having an index on the queried field?
The index is too large to fit entirely in RAM
The collection has a large number of documents
The indexed field has low cardinality (many documents share the same value)
The query uses a projection to select only a subset of fields
Which write concern level ensures that a write operation is durable even if the primary node fails?
w: all
w: majority
w: 1
w: 0
In a compound index {field1: 1, field2: -1}, what does the '-1' signify for 'field2'?
Ascending order sort.
Mark 'field2' as a sparse field.
Descending order sort.
Exclude 'field2' from the index.
Which index type in MongoDB is specifically designed to support queries that involve ranges of data?
Single Field Index
Compound Index
Geospatial Index
Text Index
What is the purpose of 'write concern' in MongoDB?
To control how many nodes must acknowledge a write operation.
To limit the number of writes per second.
To specify the level of security for write operations.
To manage data compression for write operations.