MongoDB Databases and Collections

 

•Collections 

•Documents store 

•Collections == RDBMS Tables

 •Creates the collection when you write data into the collection

•Databases 

•Holds one or more collections 

•Databases == RDBMS Databases 

•Creates the database when you first store data for that database

 

 

 MongoDBViews and Capped Collections

•MongoDB Views 

•RDBMS views Concept 

•Its Queryableobject whose contents are defined by an aggregation  pipeline 

•A view's content is computed on-demand 

•Does not persist the view contents to disk

 •Read-only 

•Does not support write operations 

•Cannot rename views

•Created in the same database as the source collection 

•To understand views, you must know MongoDB aggregation

Capped Collections 

•Fixed-size collections 

•Supports high-throughput operations

•Faster insert and retrieval of data 

•Works as circular queue or buffers 

•Makes room for new documents by overwriting the oldest documents 

•Convert normal collection to Capped collection 

•Can specify the maximum number of documents