Data Independence – Physical and Logical Data Independence

What Is Data Independence in DBMS?

What is data independence in DBMS? Data independence, the type of data transparency, can help programmers modify information definitions and organization at one level of a database system without affecting the programs or applications at the next higher level that make use of it.

Data independence provides customers with an inside look into how their data is collected and used and allows users to use this stored data for computing and presentation.

In many systems, data independence plays quite important role. So, why is data independence so important? There are many advantages of data independency in DBMS.

1. Help improve the data quality and performance.
2. The alternations in data structure won’t make any changes in application programs.
3. The data security has been enhanced and database incongruity is vastly reduced.
4. The state of being undamaged or undivided can be improved.
5. The developers can better focus on the general structure of the database.
6. Provide better services for the users.
7. Database system maintenance becomes affordable.

Now, the above advantages of data independence have been listed. Want to know more about data independence? It is essential to get acquainted with the levels or schema of a database.

There are three levels of data independence:

• The first level is the physical schema, referring to how the data is stored, indexed, and labeled.
• The next level is the conceptual level, including some data information or concepts.
• The last one is the external level, also referred to as the view schema.

Data Independence Types – Physical and Logical Data Independence

There are two types of data independence – Physical data independence and Logical data independence. In this part, we will give you separate introductions to them both and a logical vs physical data independence review will be listed.

Physical Data Independence

What is Physical data independence? Physical data independence means that the data’s physical structure can be modified but the application programs, the conceptual level, won’t be changed. The new changes are absorbed by mapping techniques. This type can help separate conceptual levels from the internal or physical levels and is easy to achieve physical data independence.

With the three levels we have mentioned above, Physical data independence relies on the presence of the internal level of the database and then the transformation from the conceptual level of the database to the internal level.

With the help of Physical data independence, the following changes will not affect the conceptual layer:

• Use a new storage device like magnetic tape, hard disk, etc.
• Change to the different data structures for storage.
• Change the access method and indexes.
• Change the location of the database.
• Use another file organization technique.

Related article: Types of Database Backup – Physical Backup Vs Logical Backup

Logical Data Independence

What is Logical data independence? Logical data independence means that users are allowed to change the logical schema without causing application programs to be rewritten.

To make the thing easy to understand, we will make an example. You may make some modifications in a document then the user view and programs should not change. If user A add something to his document, the external view for user A won’t be affected, but the internal schema of the database has been changed for both users A and B.

With the help of Logical data independence, the following changes will not affect the external layer.

• Change data definition.
• Merge two records into one.
• Add, delete, or modify any new attribute, entity, or relationship in the database.

Protect Your Data with MiniTool ShadowMaker

Now, after knowing all of the pieces of information, you can know that data independence is quite significant in the database management system (DBMS). As a property of DBMS, data independence is closely related to data security.

Related article: What Is Database Backup – Protect Your Database with a Backup

We strongly stress that to keep your data safe, you’d better have a backup plan for your important data. MiniTool ShadowMaker is a wonderful one-in-all backup expert which can perform scheduled backup and backup schemes. To download and install the program now, you can enjoy a free version for 30 days.

MiniTool ShadowMaker TrialClick to Download100%Clean & Safe

Wrapping It Up

Now, you may have understood the meaning of data independence and the difference between physical and logical data independence. Hope this article resolve your questions.