Illustrating Consistency in a Database Management System (DBMS) with a Banking Application

Let us look into a hypothetical situation involving banking application to talk about the importance of maintaining consistency in DBMS. Geek, who is one of the bank’s customers has account balances as follows:

Saving account balance: ₹500

Checking account balance: ₹300

Geek then initiates transfer of ₹100 from saving account to checking account. Afterwards, the DBMS begins transacting and deducts ₹100 from Geek’s savings account. Nevertheless, just before the DBMS can update Geek’s checking account, system failure occurs that interrupts the transaction.

Inconsistent State (Without Consistency)

If consistency was not enforced here then Geek’s saving account would have deducted ₹100 while his checking accounts would have remained unchanged.

Saving Account Balance: ₹400

Checking Account Balance: ₹300

This state is inconsistent since only part of the transfer happened leaving the database with wrong details hence total amount does not tally with its initial state.

Consistent State (With Consistency)

DBMS consistence ensures that interrupted transactions are rolled back by reverting changes made on Geek’s saving account balance.

The two accounts will remain in their original status so that despite this interruption, there is still consistent information maintained within the base.

Savings account balance: ₹500

Checking account balance: ₹300

By maintaining data consistency, the DBMS ensures that changes can be committed or rolled back completely, preventing missing or incorrect data.

This example demonstrates consistency in the DBMS to ensure the business maintains data integrity and prevents data from entering an inconsistent state despite failure or interference.

Data integrity and reliability are key in the domain of Database Management Systems (DBMS). Consistency, one of the core principles in DBMS, ensures that every transaction is made according to predefined rules and limits thus preserving the accuracy and authenticity of data kept within. The change to the database must take it from one consistent state into another.

Consistency, in DBMS, requires that any modification to a single piece of data be reflected uniformly across all linked tables as well as entities. For example, suppose you have a driver’s license database. Updating a driver’s house address should consistently appear in all relevant tables just to avoid mismatching data.

It is not enough for consistency in DBMS since it may not result in transactional correctness at all times but it plays an important role in shielding against programming errors that violate set up database constraints. To make sure that data remains reliable and intact, RDBMS go through the process of enforcing consistency to create a firm foundation for robust and trusted applications based on stored data.