Collections

MongoDB stores documents in collections. Collections are analogous to tables in relational databases. Unlike a table, however, a collection does not require its documents to have the same schema.

In MongoDB, documents stored in a collection must have a unique _id field that acts as a primary key.

MongoDB CRUD

Read Operations

Queries are the core operations that return data in MongoDB. Introduces queries, their behavior, and performances.

Cursors

Queries return iterable objects, called cursors, that hold the full result set.

Query Optimization

Analyze and improve query performance.

Distributed Queries

Describes how sharded clusters and replica sets affect the performance of read operations.

Write Operations

Write operations insert, update, or remove documents in MongoDB.

Atomicity and Transactions Describes write operation atomicity in MongoDB. Distributed Write Operations Describes how MongoDB directs write operations on sharded clusters and replica sets and the performance characteristics of these operations. Continue reading from Write Operations for additional background on the behavior of data modification operations in MongoDB.