Because MongoDB uses memory mapped files so when you run a 32-bit build of MongoDB, the total storage size of server is 2 GB. But when you run a 64-bit build of MongoDB, this provides virtually unlimited storage size. So 64-bit is preferred over 32-bit.
The 32-bit version of MongoDB is not preferred for several reasons:
- Limited Addressable Memory: The primary limitation of 32-bit systems is their inability to address more than 4 GB of RAM. In the context of a database system like MongoDB, which often deals with large datasets, having limited memory can severely impact performance. 64-bit systems can handle much larger amounts of RAM, allowing MongoDB to efficiently manage larger datasets and handle more concurrent operations.
- Document Size Limitations: In MongoDB, the maximum document size is 16 MB. With 32-bit systems, the available addressable memory can become a limiting factor in handling large documents or collections of documents.
- Index Size Limitations: The available memory also affects the ability to create and manage indexes efficiently. In a 32-bit environment, the limited address space can constrain the number and size of indexes that MongoDB can use effectively.
- Aggregation Framework Performance: The aggregation framework in MongoDB, used for complex data transformations and analysis, can benefit significantly from larger amounts of available memory. Running complex aggregation pipelines on 32-bit systems might lead to performance issues due to memory constraints.
- Lack of Support in Recent Versions: MongoDB has been moving towards dropping support for 32-bit versions in its newer releases. New features and optimizations are often designed with 64-bit systems in mind, and using a 32-bit version may mean missing out on important improvements and bug fixes.
- Industry Standard: In general, the industry has transitioned to 64-bit architectures for modern systems, and software developers and database administrators are encouraged to use 64-bit systems for performance, scalability, and compatibility with the latest technologies.
For these reasons, it is recommended to use the 64-bit version of MongoDB for any production environment or when dealing with sizable datasets.