This starts Data Control Language (DCL) commands. See Table Creation and SQL is DML, DDL, & DCL.
While a DataBase Administrator (DBA) will normally perform the DDL and DCL functions, you need to know how they work so that you can convey your needs to the DBA.Security is a major part of the RDBMS systems. SQL makes access to data very easy, so access must be scrutinized carefully for company and corporate databases. Database objects must be entered by an individual called a user and, to do this, they must be given maintenance privileges.

Each user of an SQL database is assigned a user-ID. This is a short name that identifies this individual as a person or as a member of a group. You must have a user-ID before you can access the database. The user-ID with its associated privileges determines what the user can or can not do. In a production database, a database administrator (DBA) assigns the user-ID.

The SQL standard refers to the authorization-ID. Here we refer to the user-ID as the identification used to obtain authorization through privileges to access database objects.

> The SQL1 standard allowed the user-ID to be up to 18 characters without spaces.

> DB2 allows a user-ID of up to 8 characters and uses the MVS/TSO user name.

> Informix and Ingres use the host computer’s operating system UNIX user name.

> SQL Server and Sybase allow a user-ID of up to 30 characters.

> For portability between systems, it is suggested that the user-ID be between 1 and 8 characters.