To answer this question, you need to understand the concept of database design and its impact on SQL performance. Let's go through each option to understand why it is correct or incorrect:
Option A) Removal of data redundancy - This option is incorrect because removing data redundancy is generally considered a good practice in database design, but it does not necessarily have a direct impact on SQL performance.
Option B) The introduction of data redundancy - This option is correct because introducing data redundancy can improve SQL performance in certain situations. Redundancy allows for denormalization, which can speed up query execution by reducing the number of joins required.
Option C) The introduction of non-first normal form relations - This option is incorrect because introducing non-first normal form relations can lead to data duplication and redundancy. While it may have some benefits in terms of query simplicity, it generally does not improve SQL performance.
Option D) The introduction of SQL*Plus - This option is incorrect because SQL*Plus is a command-line interface for Oracle databases and is not directly related to database design features. It does not have a significant impact on SQL performance.
The correct answer is B) The introduction of data redundancy. This option is correct because introducing data redundancy can improve SQL performance by allowing for denormalization and reducing the need for joins.