Which pattern helps avoid growing arrays indefinitely within a document in MongoDB?
Tree Pattern
Polymorphic Pattern
Subset Pattern
Bucket Pattern
What is the primary purpose of replication in MongoDB?
Ensuring high availability in case of failures
Simplifying data backups
Improving read performance
Reducing data storage costs
What is the minimum number of nodes required to set up a MongoDB replica set?
3
1
2
7
When should you consider using a hashed index in MongoDB?
For highly selective queries on a single field.
To index geospatial data for location-based queries.
When you need to perform exact value lookups.
When preserving the sort order of results is crucial.
Which sharding strategy allows for geographically distributing data to optimize for local user access?
Random sharding
Ranged sharding
Hashed sharding
Zone sharding
What is the significance of regularly rotating encryption keys used with MongoDB?
It mitigates the impact of a potential key compromise.
It enables faster data recovery after a server failure.
It improves query performance by reducing index size.
It prevents data corruption within the database.
Which operator within the $lookup stage specifies the field in the 'joined' collection that should match the 'localField'?
from
foreignField
as
localField
What role does an arbiter node play in a MongoDB replica set?
It manages backups and restores for the replica set.
It stores a copy of the data for redundancy.
It participates in elections but doesn't store data.
It processes read and write operations like other nodes.
What is the default storage engine for MongoDB versions 4.2 and later?
RocksDB
WiredTiger
InMemory
MMAPv1
Which stage of the explain plan indicates that an index was effectively used to limit the number of documents scanned?
SHARD_MERGE
COLLSCAN
IXSCAN
FETCH