Information technology -- Database languages -- SQL -- Part 4: Persistent Stored Modules (SQL/PSM)
ISO/IEC 9075 defines the SQL language. The scope of the SQL language is the definition of data structure and the operations on data stored in that structure. ISO/IEC 9075-1:2008, ISO/IEC 9075-2:2008 and ISO/IEC 9075-11:2008 encompass the minimum requirements of the language. Other parts define extensions.
ISO/IEC 9075-4:2008 specifies the syntax and semantics of statements to add a procedural capability to the SQL language in functions and procedures. It includes statements to direct the flow of control, define variables, make assignments and handle exception conditions.