MongoDB is a cross – platform , document oriented database that provides high performance, high availability and easy scalability MongoDB works on concept of collection and document.
Database
Database is physical container for collections. Each database gets its own set of files on the file system. A single MongoDB server typically has multiple interface database.
Collection:-
Collection is a group of MongoDB document. It is on equivalent to RDBMS table. A collection exists within a single database collections do not enforce a schema document within a collection can have different fields. Document A document is a set of key – value pair. Document have dynamic schema. Dynamic schema means that document in the same collection do not need to have the same set of fields and structure and common fields in a collection document may hold different types of data.
Advantage of MongoDB over RDBMS
Schema less:- MongoDB is a document database i which one collection holds different documents in which one collection holds different documents number of fields, content and size of the document can differ from one document to another.
Structure of a single object is clear
No complex join
Deep Query – ability MongoDb supports Dynamic queries on document using a document based Query language that nearly as powerfull as SQL
