If you are a database developer and you put performance as goal to achieve with your DB design...then using PL/PGSQL functions is your excellent tool. In this course we will learn all about functions : Usage benifits. Structure & structure components. Syntax to create a function. And the core part of any function which is the body ... we will see with examples of which parts the body build. We see the different kinds of implementations in the body  , starting with the variables, queries and the return results. We see with examples the different datatypes that we can RETURNS from a function We see the parameters that we can use to create a function . How to deal with different types of data that we process in a function such as ARRAY and mix data types value… How to RETURNS TABLES, RECORDS or Scalar variables. How to use special queries such as insert ,update ,delete with returning ... or use INTO clause and how to apply FOR & FOREACH Loops how to use PERFORM and EXECUTE All this we will practice with live examples on a postgresql server.