Where is mongodb data stored?
MongoDB adopts a sharded cluster architecture, shards store data in a specific range, and sharding rules define the data distribution method. Replica sets serve as redundancy mechanisms to ensure data availability. MongoDB uses BSON format to store data, data is stored in collections, and documents are the basic unit of data. The storage layer includes the WiredTiger storage engine, Journal, and memory mapping for efficient storage and access of data.
MongoDB data storage
MongoDB is a document-oriented database that adopts a distributed storage architecture. Data is stored in sharded clusters.
Sharded cluster
A sharded cluster consists of multiple shards, each of which stores a specific range of data. This allows MongoDB to scale horizontally as data grows to meet the needs of large data volumes.
Sharding rules
Sharding rules define how data is distributed across different shards. These rules can be based on field ranges, hashes, or custom expressions.
Replica Set
Each shard is usually composed of one or more replica set copies. A replica set is a redundancy mechanism that ensures that data remains accessible in the event of hardware failure or data corruption.
Data Storage Format
MongoDB uses a binary format called BSON (Binary JSON) to store data. BSON is a flexible data format that can accommodate a variety of data types, including nested documents, arrays, and binary data.
Collections
Data in MongoDB is stored in collections. Collections are similar to tables in relational databases in that they can store specific types of documents.
Document
Document is the basic unit of data in MongoDB. A document is a collection of key-value pairs, where the keys are field names and the values can be of any data type.
Storage layer
MongoDB’s storage layer consists of the following components:
- WiredTiger storage engine: Responsible for storage and retrieve data.
- Journal: A persistent log used to record all data modifications.
- Memory mapping: Allows MongoDB to quickly access data on disk, thereby improving performance.
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