Refresher of RDBMS and SQL
An RDBMS is a piece of software that manages data (represented for the end user in a tabular form) on physical hard disks and is built using the Codd's relational model. Most of the databases that we encounter today are RDBMS. In recent years, there has been a huge industry shift toward a newer kind of database management system, called NoSQL (MongoDB, CouchDB, Riak, and so on). These systems, although in some aspects they follow some of the rules of RDBMS, in most cases reject or modify them.
How is an RDBMS Structured?
The RDBMS structure consists of three main elements, namely the storage engine, query engine, and log management. Here is a diagram that shows the structure of a RDBMS:
The following are the main concepts of any RDBMS structure:
Storage engine: This is the part of the RDBMS that is responsible for storing the data in an efficient way and also to give it back when asked for, in an efficient way. As an end user of the RDBMS...