SQL

what is denormalization in sql

Denormalization is a strategy used 
on a previously-normalized database to 
increase performance. In computing, 
denormalization is the process of trying 
to improve the read performance of a database, 
at the expense of losing some write performance,
by adding redundant copies of data or by grouping data.

denormalization in sql example

Denormalization is used to combine multiple tables in order to reduce
the time required to perform queries.