What is Database

Database 

A database is a data structure that stores organized information. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records. Each of these tables would have different fields that are relevant to the information stored in the table.

Nearly all e-commerce sites uses databases to store product inventory and customer information. These sites use a database management system (or DBMS), such as Microsoft Access, File Maker Pro, or MySQL as the "back end" to the website. By storing website data in a database, the data can be easily searched, sorted, and updated. This flexibility is important for e-commerce sites and other types of Dynamic websites.

Early databases were relatively "flat," which means they were limited to simple rows and columns, like a Spreadsheet. (See also "flat file database"). However, today's relational databases allow users to access, update, and search information based on the relationship of data stored in different tables. Relational databases can also run queries that involve multiple databases. While early databases could only store text or numeric data, modern databases also let users store other data types such as sound clips, pictures, and videos.

Types of databases

Databases have evolved since their inception in the 1960 beginning with hierarchical and network databases, through the 1980 with Object oriented Database, and today with SQL and No SQL databases and cloud database.

In one view, databases can be classified according to content type: bibliographic, full text, numeric and images. In computing, databases are sometimes classified according to their organizational approach. There are many different kinds of databases, ranging from the most prevalent approach, the relational database, to a  distributed databases, cloud database. , graph database or NoSQL database.

Relational database

relational database , invented by E.F code at IBM in 1970, is a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways.

Relational databases are made up of a set of tables with data that fits into a predefined category. Each table has at least one data category in a column, and each row has a certain data instance for the categories which are defined in the columns.

The Structured Query Language (SQL) is the standard user and application program interface for a relational database. Relational databases are easy to extend, and a new data category can be added after the original database creation without requiring that you modify all the existing applications.

Distributed database

A distributed database is a database in which portions of the database are stored in multiple physical locations, and in which processing is dispersed or replicated among different points in a network.

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 that has been optimized or built for a virtualized environment, either in a hybrid cloud, public cloud or private cloud. Cloud databases provide benefits such as the ability to pay for storage capacity and bandwidth on a per-use basis, and they provide scalability on demand, along with high availability.

A cloud database also gives enterprises the opportunity to support business applications in a software as a system deployment.

SQL database

SQL databases are effective for big data performance issues that relational databases aren't built to solve. They are most effective when an organization must analyze large chunks of unstructured data or data that's stored across multiple   virtual servers in the cloud.

Advantages

• Reduced data redundancy.
• Also, there is reduced updating errors and increased consistency.
• Easier data integrity from application programs.
• Improved data access to users through the use of host and query languages.
• Data security is also improved.
• Reduced data entry, storage, and retrieval costs.

Disadvantages

• Complexity: Databases are complex hardware and software systems.
• Cost: It requires significant upfront and ongoing financial resources.
• Security: Most leading companies need to know that their Database systems can securely store data, including sensitive employee and customer information.
• Compatibility: There is a risk that a DBMS might not be compatible with a company’s operational requirements. 

Object-oriented database

Items created using object-oriented programming  languages are often stored in relational databases, but object-oriented databases are well-suited for those items.

An object-oriented database is organized around objects rather than actions, and data rather than logic. For example, a multimedia record in a relational database can be a definable data object, as opposed to an alphanumeric value.

Graph database

A graph-oriented database, or  graph database, is a type of No SQL database that uses graph database to store, map and query relationships. Graph databases are basically collections of nodes and edges, where each node represents an entity, and each edge represents a connection between nodes.