What is database?

What is database?

• What is Data?
• What is a Database?
• Evolution of databases
• What is a Database Management System (DBMS)?
• Types of DBMS
• Relational database
• Distributed database
• Cloud database
• NoSQL database
• Object-oriented database
• Graph database
• What is SQL?

What is Data?

We can explain data in simple word facts related to any object in consideration.

For example your age, name, height, etc. are some data. A file, document, etc can also be considered data.

What is a Database?

A database can be defined as a collection of coherent, meaningful data. Database support and manipulation of data.

The phrase collection of coherent data needs to have a point of reference to be understood.

A simple point of reference would be the example of a Mobile, this would generally contain:

• A mobile name
• A mobile model
• A mobile color
• A mobile weight
• A mobile height
• A mobile width
• A mobile features
• Etc.

Evolution of databases

The first general purpose DBMS was designed by Charles Bachman in early 1960 and called as Integrated Data Store.

In 1966, IBM released the IMS which is based on the hierarchical data model and assumes all data relationship to be structured as hierarchies.

The 1980’s with object-oriented databases, and today with SQL and NoSQL databases and cloud databases.

What is a Database Management System (DBMS)?

A Database Management System (DBMS) is essentially a collection of interrelated data and a set of programs to access this data.

This collection of data is usually called the database. Database systems are designed to maintain large volumes of data.

DBMS are not a new concept, this was first implemented in 1960s by Charles Bachman and called as Integrated Data Store (IDS).

Types of DBMS

Relational database – A Relational Database Management System (RDBMS) is a Database Management System (DBMS) that is based on the relational model as introduced by E. F. Codd.

Strictly speaking it should also satisfy Codd’s 12 rules, but in practice there is no DBMS that satisfies all these rules.

In this type of DBMS defines database relationships in form of tables, also known as relations.

Examples of relational database management systems include MySQL, Oracle, and Microsoft SQL Server database.

Distributed database – Distributed Database System is stored the on several computers. The computers in a distributed system communicate with one another through various communication media, such as high-speed networks or telephone lines.

They do not share main memory or disks. The computers in a distributed system may vary in size and function, ranging from workstations up to mainframe system.

Distributed databases can be homogeneous or heterogeneous. All the physical locations in a homogeneous distributed database system have the same underlying hardware and run the same operating systems and database applications. The hardware, operating systems or database applications in a heterogeneous distributed database may be different at each of the locations.

Cloud database – A cloud database is a database service which is build and access through cloud platform. Cloud computing provide a traditional database with the added flexibility of cloud computing.

For implement the database, user install software on cloud infrastructure.

Users host databases without buying dedicated hardware. And cloud database access through a web interface or vendor-provided API.

Why cloud database -

• Ease to access
• Scalability
• Disaster recovery

NoSQL database – A NoSQL originally referring to non SQL or non-relational is a database that provides a mechanism for storage and retrieval of data.

NoSQL databases are used in real-time web applications and big data and their use are increasing over time.

In NoSQL database huge amount of data need to be stored and retrieved. The NoSQL database is growing continuously and you need to scale the database regular to handle the data.

Key-value stores, Document database, Wide-column stores, Graph stores are all the family of NoSQL database.

Object-oriented database – OODBMS represent significant advance over other DBMS. While other DBMS are designed to handle structred data, an OODBMS is designed to store data from variety of media sources, such as photographs and text, and produce work, as output, in a multimedia format.

Graph Database - Very simply, a graph database is a database designed to treat the relationships between data as equally important to the data itself. It is intended to hold data without constricting it to a pre-defined model. Instead, the data is stored like we first draw it out – showing how each individual entity connects with or is related to others.

What is SQL? - Structured Query language (SQL) pronounced as "S-Q-L" or sometimes as "See-Quel" is actually the standard language for dealing with Relational Databases.

SQL is a language to operate databases; it includes database creation, deletion, fetching rows, modifying rows, etc. Relational databases like MySQL Database, Oracle, MS SQL server, Sybase, etc.