As information technology era started to grow and many industries went from manual to automated work; the need of storing large data and managing it efficiently arises. Hence, countering this need DATABASE SYSTEMS came into existence. Following is a brief introduction about the database systems and their functionalities.

What is a database?

Database is considered to be a collection of inter-related data in an organized and easy to retrieve manner

Database Management System (DBMS)

A system/program that manages Database effectively is called a Database Management System (DBMS).

How DBMS operates:

How DBMS operates?

What is a Relational Database (RDBMS)?

A RDBMS is a collection of relations (tables) or 2-dimensional Tables.

Keep in mind:

How RDBMS system works?

  • A table is a basic storage structure unit of a RDBMS
  • Security and Authorization methods are well defined
  • Protect Data integrity
  • Can be accessed and modifies by executing structured query language statements
  • Uses a set of relational Operators Selection, Projection, Join and a set operation Union, Intersection etc.
  • Contains a collection of tables with No Physical Pointers as we use Primary Key & Foreign Key to access and relate data
  • Keeps logical representation of data independent of its physical storage characteristics
  • In most RDBMS, SQL is used as a language interpreter
  • SQL is a non-procedural language i.e. user only tell "What To Do" not "How To Do"
  • SQL is used for:
    • Data Manipulation
    • Data Definition
    • Data Administration
    • All are expressed as an SQL statement or command.

Examples

There are many interesting examples throughout the chapters to learn from. However at this moment there are no interactive "do-it-yourself" editors.

References

At the end of the tutorial you will find a complete reference list with all storage engines, data types, methods, statements , etc...

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