Advantages of Lossless Decomposition

What is Lossless Decomposition?

Lossless join decomposition is a decomposition of a relation R into relations R1, and R2 such that if we perform a natural join of relation R1 and R2, it will return the original relation R. This is effective in removing redundancy from databases while preserving the original data....

Example of Lossless Decomposition

— Employee (Employee_Id, Ename, Salary, Department_Id, Dname)...

Advantages of Lossless Decomposition

Reduced Data Redundancy: Lossless decomposition helps in reducing the data redundancy that exists in the original relation. This helps in improving the efficiency of the database system by reducing storage requirements and improving query performance. Maintenance and Updates: Lossless decomposition makes it easier to maintain and update the database since it allows for more granular control over the data. Improved Data Integrity: Decomposing a relation into smaller relations can help to improve data integrity by ensuring that each relation contains only data that is relevant to that relation. This can help to reduce data inconsistencies and errors. Improved Flexibility: Lossless decomposition can improve the flexibility of the database system by allowing for easier modification of the schema....

Disadvantages of Lossless Decomposition

Increased Complexity: Lossless decomposition can increase the complexity of the database system, making it harder to understand and manage. Increased Processing Overhead: The process of decomposing a relation into smaller relations can result in increased processing overhead. This can lead to slower query performance and reduced efficiency. Join Operations: Lossless decomposition may require additional join operations to retrieve data from the decomposed relations. This can also result in slower query performance. Costly: Decomposing relations can be costly, especially if the database is large and complex. This can require additional resources, such as hardware and personnel....

Conclusion

In Conclusion, a lossless decomposition is an important concept in DBMS that ensures that the original relation can be reconstructed from the decomposed relations without any loss of information. The use of Armstrong’s axioms and decomposition algorithms such as BCNF and 3NF can help achieve lossless decomposition in practice....

Question Asked in GATE

Q.1: Let R (A, B, C, D) be a relational schema with the following functional dependencies:...