SQL Joins vs Single Table : Performance Difference?

Question

I am trying to stick to the practice of keeping the database normalized, but that leads to the need to run multiple join queries. Is there a performance degradation if many quer

Answer 1

Keep the Database normalised UNTIL you have discovered a bottleneck. Then only after careful profiling should you denormalise.

In most instances, having a good covering set of indexes and up to date statistics will solve most performance and blocking issues without any denormalisation.

Using a single table could lead to worse performance if there are writes as well as reads against it.