Getting Started with NoSQL

Questions: 1. Please compile the database model types in chronological order and give a database for each of the model types as an example? 2. Please compare and contrast Relational Databases and NoSQL Databases briefly? Answers: 1: Following are three database model types: Hierarchical databases are organized in the pyramid form which is narrow at the top and broad at the bottom. Similar or related records are grouped together in order to form a high-level record. For e.g. File System Network model is an upside-down tree which has inter-connected network of records. In these type of databases, children are known as members and parents are known as owners. Relational data model has data stored in different tables and each table has a unique identifier which distinguishes each row. They provide more flexibility as compare to hierarchical and network databases. For e.g. Oracle. 2: Relational databases are known as Relational Databases (RDBMS); whereas NoRelational database are known as non-relational or distributed database. Relational databases are based on table structure and No-Relational databases are document-based, key-value pair or graph-based. This means that relational databases represent databases in the form of tables which contains n number of rows of data where as NoSQL databases are collection of key-value pair which does not possess standard schema definitions. This depicts that RDBMS has a pre-defined schema whereas NoSQL databases have dynamic schema for the data. RDBMS are vertically scalable. NoSQL databases are horizontally scalable. RDBMS are scaled by increasing the hardwares horse-power whereas NoSQL is scaled by enhancing the database servers in the resource pool. RDBMS uses relational i.e. structured query language fro defining and manipulating the data. NoSQL has UnQL i.e. Unstructured Query Language. Examples of Relational database are MyRelational, Oracle, Postgres and MS-SQL. Examples of NoSQL database: MongoDB, BigTable, Cassandra, Hbase, and CouchDb. References Vaish, G. (2013).Getting started with NoSQL. Birmingham: Packt Publishing. Yang, C. (1986).Relational databases. Englewood Cliffs, N.J.: Prentice-Hall.