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How does MongoDB maintain consistency?
How does MongoDB ensure consistency? MongoDB is consistent by default: reads and writes are issued to the primary member of a replica set. Applications can optionally read from secondary replicas, where data is eventually consistent by default.
What is compression in MongoDB?
Compression. With WiredTiger, MongoDB supports compression for all collections and indexes. Compression minimizes storage use at the expense of additional CPU. By default, WiredTiger uses block compression with the snappy compression library for all collections and prefix compression for all indexes.
What are the advantages limitations and disadvantages of NoSQL?
Advantages and Disadvantages of NoSQL databases – what you should know
- Less mature. RDBMSs have been around a lot longer than NoSQL databases.
- Less support.
- Business intelligence and analytics.
- Administration.
- No advanced expertise.
- Advantages of NoSQL databases.
- Elastic scalability.
- Big data applications.
When we should not use MongoDB?
MongoDB would not be well suited for applications that need:
- Multi-Object Transactions: MongoDB only supports ACID transactions for a single document.
- SQL: SQL is well-known and a lot of people know how to write very complex queries to do lots of things.
How does MongoDB store compressed data?
Compression is enabled by default for collections and indexes in the WiredTiger storage engine. To explicitly set the compression for the replica at startup, specify the appropriate options in the YAML config file. use the command line option –wiredTigerCollectionBlockCompressor.
What are the limitations of a MongoDB collection?
Max document size: 16 MB (we all knew this one, right?) Max document nesting level: 100 (documents inside documents inside documents…) If you set a limit of documents in a capped collection, this limit can’t be more than 2**32. Otherwise, number of documents is unlimited.
Are there any issues with ACID transactions in MongoDB?
However, two critical concerns that have been a thorn on MongoDB’s side over the years are that of data durability and ACID transactions. MongoDB has been taking incremental steps to solve these issues leading to the recent 4.0 release with multi-document transaction support.
Do you need transaction to write document in MongoDB?
With a document based structure and denormalized data model, there will be a minimized need for transactions. Since MongoDB allows document embedding, you don’t necessarily need to use a transaction to meet a write operation.
Why is MongoDB good for web app development?
Web app developers initially adopted MongoDB for its ability to model data as “schemaless” JSON documents. This was a welcome relief to many who were previously bitten by the rigid structure and schema constraints of relational databases.