What is Data Inconsistency?

Data inconsistency is the scenario in DBMS where there are more than 2 tables within a database that work with the same data but receive it from different inputs. In simpler words, Data Inconsistency is the concept where there are conflicts or different copies of the same data in the database. This issue occurs when data stored in different locations within the database do not match or are not synchronized. The possibilities through which this occurs are software bugs, human errors, hardware failures, and many more situations.

Let’s understand the concept of Data Inconsistency through an example:

Example of Data Inconsistency:

Consider a situation where an organization maintains multiple databases for different departments. The Financial Table stores the employee’s salary data, while Human Resources Table consists of employee records and salaries.

Now, let’s assume that there is a system that is used for synchronizing or sending data from both tables into a Target Database. Due to a technical issue, the synchronization process fails to detect the data inconsistency, which results in the conflict records as shown in the above diagram in Target Database.

We can easily notice that John’s salary is repeated twice in Target Database with different values. This data inconsistency arose due to the synchronization process did not reconcile the conflicting salary values for John in the Financial and Human Resource tables.

The database is the collection of structured records that are used in various scenarios to gain useful insights, perform CRUD operations, and many other things. The data stored in the Database is in the form of rows and columns, we mostly call them as records. There are various tables that store and represent the data/records to the user. In these tables, there may be a situation where the data stored as records may be inconsistent. This leads to Data Inconsistency in the database. In this article, we will explore the concept of Data Inconsistency, will understand the concept through a simple example, explore the problems caused due to Data inconsistency, and lastly will see the disadvantages of Inconsistent Data.