Final answer:
De-normalization is the process of restructuring a database by merging tables and increasing redundancy to improve read performance, typically used in data warehousing where high query performance is needed. Option d.
Step-by-step explanation:
The process you're referring to is called de-normalization. This is a strategy used in database optimization where the focus is on performance rather than strictly adhering to normalization principles. Normalization involves organizing a database to reduce redundancy and improve data integrity. However, de-normalization takes the normalized entities and sometimes merges them, increasing redundancy in exchange for faster access times when queries that join these tables frequently are run. This technique is useful in data warehousing where read operations are significantly more common than writes and when system performance is critical.
In the specific context of your question, de-normalization might involve combining two tables that were previously split so that all the data is in a single table, thereby reducing the need to join tables during queries. It can also involve adding redundant data to a table, or creating new aggregate tables that speed up the retrieval of data.