The ability to grant and revoke logons for database users is controlled by the EXECUTE privilege on the DBC.LogonRule macro. User DBC has this privilege by default. You must grant the privilege to any other user who needs to use the GRANT LOGON or REVOKE LOGON statement. For an example:
GRANT EXECUTE ON DBC.LogonRule
See Creating the Security Administrator User for other administrator privileges.
When an administrator with the GRANT EXECUTE ON DBC.LogonRule privilege submits a GRANT LOGON or REVOKE LOGON statement, the DBC.LogonRule macro adds or deletes a row in the DBC.logonRules table for the affected user. See "DBC.LogonRulesV" in Teradata Vantage™ - Data Dictionary, B035-1092 and "GRANT LOGON/REVOKE LOGON" in Teradata Vantage™ - SQL Data Control Language, B035-1149.