Oracle 10g中的用户何时启用角色?

我使用C#4中的ADO.NET为组件设置测试上下文。

我以sysdba的身份执行以下SQL:

new[]
{
    "create user \"{0}\" identified externally default tablespace USER_DATA temporary tablespace TEMP profile DEFAULT"
    .FormatWith( Config.QualifiedUserName ),
    "create role {0}"
    .FormatWith( Config.RoleName ),
    "grant {0} to \"{1}\""
    .FormatWith( Config.RoleName, Config.QualifiedUserName ),
    "insert into doc.application( id, name ) values( {0}, '{1}' )"
    .FormatWith( Config.AppId, Config.AppName ),
    "insert into doc.appl_role( application, role, description ) values( {0}, '{1}', '{2}' )"
    .FormatWith( Config.AppId, Config.RoleName, Config.RoleDescription ),
    "create table {0}.{1} ( ID number primary key, VERSION number, NAME varchar(100) )"
    .FormatWith( Config.TestSchema, Config.TestTable ),
    "insert into {0}.{1} (ID, VERSION, NAME) values ('{2}', '{3}', '{4}')"
    .FormatWith( Config.TestSchema, Config.TestTable, Config.TestRowId, 1, Config.TestRowName ),
    "grant select, insert, update, delete on {0}.{1} to {2}"
    .FormatWith( Config.TestSchema, Config.TestTable, Config.RoleName ),
    "grant create session to \"{0}\""
    .FormatWith( Config.QualifiedUserName )
} 

public struct Config
{
    public const Int32 TestRowId = 1;
    public const Int32 AppId = 99999;
    public const String AppName = "OraceUtils";
    public const String RoleName = "ORACLE_UTILS_BASE";
    public static readonly String RoleDescription = "For testing {0}".FormatWith( AppName );
    public static readonly String QualifiedUserName = @"{0}\{1}".FormatWith( Domain, UserName );
    public const String DataSource = "TESTDB";
    public const String Domain = "BI";
    public const String UserName = "ORACLE_TEST_USER";
    public const String UserPassword = [for my eyes only];
    public const String TestSchema = "CI";
    public const String TestTable = "ROLE_PROVIDER_TEST_TABLE";
    public const String TestRowName = "Arne And";
}

据我所知,仅仅授予用户一个角色并不能启用它。但是,在执行上面的SQL之后,用户BI\ORACLE\u TEST\u user可以很好地使用表角色\u PROVIDER\u TEST\u table。角色ORACLE\u UTILS\u BASE也显示在SESSION\u角色中。

我认为情况正好相反,即用户只有在发出“SET ROLES ORACLE\u UTILS\u BASE,[任何其他角色]”之后才能访问。