Does storing aggregated data go against database normalization?

Question

On sites like SO, I'm sure it's absolutely necessary to store as much aggregated data as possible to avoid performing all those complex queries/calculations on every page load. For instance, storing a running tally of the vote count for each question/answer, or storing the number of answers for each question, or the number of times a question has been viewed so that these queries don't need to be performed as often.

But does doing this go against db normalization, or any other standards/best-practices? And what is the best way to do this, e.g., should every table have another table for aggregated data, should it be stored in the same table it represents, when should the aggregated data be updated?

Thanks

Answer 1

Storing aggregated data is not itself a violation of any Normal Form. Normalization is concerned only with redundancies due to functional dependencies, multi-valued dependencies and join dependencies. It doesn't deal with any other kinds of redundancy.