MySQL: Varchar MySQL Joining

Often we have to join MySQL tables with CHARACTER columns. Here are some reasons where we may lag behind with the performance compared to INT fields.

With the increasing length CHAR keys performance degrade significantly. Short index values can be processed more quickly than long ones. As a result, when you index a column, ask whether it’s sufficient to index partial column values rather than complete values. This technique of indexing a column prefix can be applied to string data types.