What is Database? (Part 1)

Database is a containers of data. If you went to a library, you will notice that library stores books, we can say that is is a database of books

At it’s simplest expression, database is a collection of information which at the stake often called data and stored at a server. Data is oftenly organized so that it could be easily retrieved, edited, and managed in some significant ways by the end-user. Data can be something simple such a personal information about customer or client. It can also be sales, inventory, calls or anything that needs to be tracked. It’s up to the user to set the value of data needs to be used and the format that will be used.

When we use a database, the data isn’t stored on our compute’s harddisk but it’s uploaded digitally on the cloud which often we call as a server, at someplace we might don’t know. Database management system (DBMS) query are made to receive information. The part called back-end. To provide data in consequential way for user, web developers make a website and ease to use database software. This part is called front-end/

Even if there’s many other database model such as network models and hierarchical, the model of relational database is the most common. Relational databaase model was developed in 1970’s and it’s still most common model till this day. The data stored in relation, taking form of table made of rows (record) and  collumn (fields). To interact and access data contained in relational database, the user need to use relational database management system or oftenly called RDBMS. Most common or used language to query and manage is SQL or oftenly called Structured Query Language.

SQL : The Classic

SQL is the language that most IT expert use to interact with the relational databases. Those interaction are oftenly called transaction. To be effcient and accurate, transactiion must be atomic, consistency, isolation and durability (ACID). Atomic means that transaction is all or nothing. Consistency are means the fact that database must remain in aconsistent state , before and after the transaction. Isolation means all of those transaction must be independent to one another. Durability means to the fact that transaction should be done after the user has been informed of a successful transaction.

The best example to explain SQL and ACID properties is a banking system. For example if we want to transfer fund to friend’s account. There will be a series of queries made to make the money transfer possible from one account to another. All queries must be accepted and completed in order for completing the transaction. If the call fails, transaction wouldn’t be completed and the money will be kept (atomic). The information of each account won’t effected by transaction (consistency). Each query made to the database will related to the transaction (isolation). Once the transaction success, it won’t be able to cancelled (durability).

Best-known RDBMS using SQL to query and create database are IBM DB2, Microsoft Access, MySQL, and Oracle.

NewSQL could be referred to as the modern relational databases languages. These are based on the relational database model and the SQL query language but offers better consistency. Some of them offer solid ACID guarantees. Social media platforms such as Facebook, Twitter or Instagram are the best examples of the use of NoSQL and NewSQL. These require the ability to process astonishing amounts of data very quickly but (mostly) don’t need the ACID properties.

Reference : https://www.kohezion.com/blog/4-examples-database-application/