NoSQL MongoDB(1)

NoSQL databases currently in use can be divided into four broad categories: 1.Key-value data stores: Data is stored in key-value pairs, and values ​​are retrieved through keys. For example redis, dynomite, voldemort. 2.Column-based databases: These databases organize data stored in tables, similar to RDBMS. However, they store content in columns rather than rows. Very good for data warehouse applications. For example Hbase, Cassandra, Hypertable. 3.Document-based databases: Data is stored and organized as a collection document. These documents are flexible and can have any number of fields per document. For example CouchDB, MongoDB. 4.Graph-based data-stores: Such databases are used for data storage and retrieval in computer science graph theory. Focus on data interconnection in different parts. The units of data are visualized as nodes and the relationships between them are defined as edges connecting the nodes. For example Neo4j. MongoDB components: 1.Database: There can be multiple databases, each acting as an independent container. Each database can contain one or more collections. 2.Collection: A collection is a group of documents. Logically equivalent to a table in a relational database. But unlike tables, there is no need to define a data structure beforehand when storing data in a collection. 3.Document: The unit in…