Why might you deliberately denormalize a schema?
Options
- To remove all the redundancy that exists in the schema
- To speed up reads by avoiding joins, with duplicated data (Correct option)
- To enforce the constraints of the schema more strictly
- Because normalization is deprecated in modern databases
Answer
To speed up read-heavy queries by avoiding joins, accepting duplicated data and harder updates
Why
Normalization splits data so each fact is stored once (no duplicates), which keeps updates simple and consistent.
Denormalization deliberately copies some data (e.g. storing comment_count on the post, or the customer name on the order) so frequent reads avoid joins and are faster.
The cost: you must keep the copies in sync when data changes.
Remember
Denormalize = duplicate data on purpose for faster reads.