In this article Data abstraction in DBMS we give the information about In DBMS, data abstraction is divided into three main levels Physical Level, Logical Level and View Level.
Data abstraction in DBMS:-
Data Abstraction is an important concept in DBMS which organizes it in a structured manner so that the users can easily identify and use the data. This concept is used in database management systems (DBMS) to allow users to separate programming content from actual data.
In DBMS, data abstraction is divided into three main levels:
This level is the lowest level and shows the actual structure of the data. It includes physical structure of data, organization of data, and technical information of data files.
This level shows the logical structure of the data, allowing users to understand the data. This includes information about data access, how the data is logically viewed, and the rules in place.
This level is the highest level and provides the interface to the user to view and manipulate the data. Here the user views the data as per his needs, such as reports, forms, recommendations, etc.
With the help of these three levels, data abstraction helps users contextualize and simplify data in a DBMS.
Data independence in DBMS:-
Data independence is an important concept in DBMS that makes data independent from programs and helps in managing it in a structured manner. This allows the physical structure and logical structure of data to be managed separately and used together, without affecting the programs.
In a DBMS, there are two main types of data independence:
Logical Data Independence:
It is related to the logical structure of the data. In this, changes made in the logical structure of data do not affect the programs. For example, if a change is made to the structure of the data (such as adding, deleting, or changing fields), programs have no effect on it.
Physical Data Independence:
It is related to the physical structure of the data. In this, changes made in the physical structure of data have no effect on the programs. For example, if a change is made to the physical structure of the data (such as changing the file type of the database, moving data to another disk), programs have no effect on it.
These two types of data independence allow changes to be made to the database design without affecting the existence of any program. It ensures users access to improved, developed and upgraded databases and allows programs to work independently.