How can be our db is light and fast

It slightly complicated. Please use the attached script and follow instruction.

 

Basically there is one COMMENTED piece of sql, which you should execute in a separate query window. The output of that query execution must be pasted in the area mentioned and then the whole script should be executed.

 

Please make sure you use appropriate database.

 

Script is quite safe, it is not altering / creating / deleting absolutely any object