Question

Why is Concurrency Control needed? What is the problem called?

1) Read-Write Problem
2) Write-Write Problem
3) Write-Read Problem
4) Read-Only Problem

Answer 1

Concurrency control is essential in database management to manage conflicts when multiple transactions occur simultaneously. It addresses issues like the Read-Write, Write-Write, and Write-Read Problems, ensuring database integrity and reliability.

Step-by-step explanation:

Concurrency control is needed in database systems to ensure that transactions occur in an orderly and controlled manner, by handling potential conflicts when multiple users access and manipulate the data simultaneously. One of the main problems that concurrency control aims to solve is the Read-Write Problem, where a transaction reads a data item while another transaction is writing to it, potentially leading to inconsistencies.

Write-Write Problem occurs when multiple transactions attempt to write to the same data item concurrently, risking data integrity. The Write-Read Problem, also known as the dirty read problem, happens when a transaction reads data written by another, uncommitted transaction, which is problematic if the latter transaction is rolled back.

The issue of concurrency control is critical because, without it, the database integrity can be compromised, leading to errors in data, transaction failures, and system unreliability, which are significant problems in any database management system. Effective concurrency control relies on implementing protocols that prevent phenomena such as lost updates, temporary inconsistency, and permanent inconsistency, ensuring that the database remains in a