Defining a Database Using Non-SQL › Security Checking

Security Checking

The schema and subschema compilers maintain security to ensure that no unauthorized person uses the compilers to perform secured operations. The compilers perform security checking operations when:

• The verb is SIGNON, VALIDATE, or GENERATE
• The SET OPTIONS statement contains REGISTRATION OVERRIDE
• The component type is SCHEMA
• The component type is SUBSCHEMA
• The statement is the first statement of the session

In any of the above cases, the compiler determines whether the requested operation is secured. If the operation is not secured, the compiler bypasses the security check and begins processing the statement. If the operation is secured, the compiler checks the user's description in the dictionary to determine whether the user is authorized to perform an operation. If the user is authorized, the compiler processes the input statement; if not, the compiler issues an error message.

Types of Security Checked

The compilers check four kinds of security:

• Compiler security
• Registration override security
• Verb security
• Component security

Each kind of security is presented separately below; each topic includes the following kinds of information:

• When security is checked
• How security is turned on or off
• How the compiler determines who the issuing user is
• What constitutes an authorized user