Introduction to Databases

Physical level: The lowest level of abstraction. It describes how the data are actually stored.
Logical Level: This level describes the data stored in database, and the relationships that exist among the data. It describes the entire database in terms of small number of relatively simple structure. For example:

A database is a collection of logically interrelated data and description of this data, designed to meet the information needs for organization. The primary objective of creating a database is to store, update and retrieve data efficiently and use it for analysis. The data stored can also include any transient data such as input documents, reports and intermediate results obtained during processing of the data. To achieve this, database must have different characteristics and some of them are:

It should have a structure which deals with data types and data behavior.
It should have a proper retrieval method which could be a declarative query language (like SQL, which we'll talk about in this article) or a procedural database programming language (like Java or Python).
The storing and retrieving process should be quick and correct
Data must be secure and must be protected from unauthorized access

Category: Machine Learning