Mongo DB

Appears to have the lead among document-oriented databases. Easy to install, set-up, run.

Also see Erlang#CouchDB, may be better for distributed document database ...

Is Mongo DB core function ?

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MongoDB (from humongous) is a cross-platform document-oriented database. Classified as a NoSQL database, MongoDB eschews the traditional table-based relational database structure in favor of JSON-like documents with dynamic schemas (MongoDB calls the format BSON) ...


From Wikipedia:

Some of the main features include:

Document Oriented

Instead of taking a business subject and breaking it up into multiple relational structures, MongoDB can store the business subject in the minimal number of documents. For example, instead of storing title and author information in two distinct relational structures, title, author, and other title-related information can all be stored in a single document called Book, which is much more intuitive and usually easier to work with.

Ad Hoc Queries

MongoDB supports search by field, range queries, regular expression searches. Queries can return specific fields of documents and also include user-defined JavaScript functions.


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 provides high availability with replica sets. A replica set consists of two or more copies of the data. Each replica set member may act in the role of primary or secondary replica at any time. The primary replica performs all writes and reads by default. Secondary replicas maintain a copy of the data on the primary using built-in replication. When a primary replica fails, the replica set automatically conducts an election process to determine which secondary should become the primary. Secondaries can also perform read operations, but the data is eventually consistent by default.

Load Balancing

MongoDB scales horizontally using sharding. The user 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 can 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,[8] 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. Instead of storing a file in a single document, GridFS divides a file into parts, or chunks, and stores each of those chunks as a separate document.

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.

Server Side JavaScript

JavaScript can be used in queries, aggregation functions (such as MapReduce), and sent directly to the database to be executed.

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.

MongoDB as a Service

The Magic of the Cloud

Create databases and replica set clusters on-demand. Scale up and down with ease. Never think about machines and never install software. We give you a connection string, and you are good to go! ...

Web-based Database Management

Our admin tools allow you to search, visualize, and modify data with ease as well as help you optimize your queries and indexes. We guarantee that you’ll love these tools and that you won’t be able to live without them.

Web-based management tools

Our MongoDB admin tools provide beautiful data visualization and powerful database controls. Save common searches, set up tabular data views, and edit documents using a built-in JSON editor. Manage current database operations, stream real-time logs, and perform other essential DBA functions through a MongoDB GUI we're sure you'll love.

IBM Dev Tutorials
Search IBM Dev for 'mongodb
Top 5 syntactic weirdnesses to be aware of in MongoDB


MongoDB object modeling for Node.js

MS Windows

Easy install, apparently. Traps ?


If you are running any edition of Windows Server 2008 R2 or Windows 7, please install a hotfix to resolve an issue with memory mapped files on Windows.



Also See



Search wiki for 'mongodb'

Last modified 3 years ago Last modified on 05/12/2015 07:48:58 AM