The following is a brief summary of some of the main features:
- Ad hoc queries
- Any field in a MongoDB document can be indexed (indices in MongoDB are conceptually similar to those in RDBMSes). Secondary indices are also available.
- MongoDB supports master-slave replication. A master can perform reads and writes. A slave copies data from the master and can only be used for reads or backup (not writes). The slaves have the ability to select a new master if the current one goes down.
- Load balancing
- MongoDB scales horizontally using sharding. The developer chooses a shard key, which determines how the data in a collection will be distributed. The data is split into ranges (based on the shard key) and distributed across multiple shards. (A shard is a master with one or more slaves.)
- MongoDB can run over multiple servers, balancing the load and/or duplicating data to keep the system up and running in case of hardware failure. Automatic configuration is easy to deploy and new machines can be added to a running database.
- File storage
- MongoDB could be used as a file system, taking advantage of load balancing and data replication features over multiple machines for storing files.
- This function, called GridFS, is included with MongoDB drivers and available with no difficulty for development languages (see "Language Support" for a list of supported languages). MongoDB exposes functions for file manipulation and content to developers. GridFS is used, for example, in plugins for NGINX. and lighttpd
- In a multi-machine MongoDB system, files can be distributed and copied multiple times between machines transparently, thus effectively creating a load balanced and fault tolerant system.
- MapReduce can be used for batch processing of data and aggregation operations. The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used.
- Capped collections
- MongoDB supports fixed-size collections called capped collections. This type of collection maintains insertion order and, once the specified size has been reached, behaves like a circular queue.
For further information on the points listed look up the MongoDB Developer Manual
Read more about this topic: Mongo DB
Other articles related to "main features":
... Start Search bar (Windows Vista/7 like) allows to quickly search amongst any SyItem configured on menu Windows Start Menu wrapper SyMenu exposes through Start Search bar a customizable number of programs linked in host PC Windows Start menu too. ...
Famous quotes containing the words features and/or main:
“Each reader discovers for himself that, with respect to the simpler features of nature, succeeding poets have done little else than copy his similes.”
—Henry David Thoreau (18171862)
“I do not deny that there may be other well-founded causes for the hatred which various classes feel toward politicians, but the main one seems to me that politicians are symbols of the fact that every class must take every other class into account.”
—José Ortega Y Gasset (18831955)