Sybase 12.4.2 manual Database object names and prefixes, Special groups, 367

CHAPTER 10 Managing User IDs and Permissions

Special groups

The SYS group

The PUBLIC group

When a database is created, two groups are also automatically created. These are SYS and PUBLIC. Neither of these groups has passwords, so it is not possible to connect to the database as either SYS or as PUBLIC. The two groups serve important functions in the database.

The SYS group is owner of the system tables and views for the database, which contain the full description of database structure, including all database objects and all user IDs.

For a description of the system tables and views, together with a description of access to the tables, see Chapter 15, “System Tables” and Chapter 16, “System Views” in Adaptive Server IQ Reference Manual.

When a database is created, the PUBLIC group is automatically created, with CONNECT permissions to the database and SELECT permission on the system tables.

The PUBLIC group is a member of the SYS group, and has read access for some of the system tables and views, so that any user of the database can find out information about the database schema. If you wish to restrict this access, you can REVOKE PUBLIC's membership in the SYS group.

Any new user ID is automatically a member of the PUBLIC group and inherits any permissions specifically granted to that group by the DBA. You can also REVOKE membership in PUBLIC for users if you wish.

Database object names and prefixes

The name of every database object is an identifier. The rules for valid identifiers are described in Chapter 6, “SQL Language Elements” in Adaptive Server IQ Reference Manual.

In queries and sample SQL statements throughout this guide, database objects from the sample database are generally referred to using their simple name. For example:

SELECT *

FROM employee

Tables, procedures, and views all have an owner. The owner of the tables in the sample database is the user ID DBA. In some circumstances, you must prefix the object name with the owner user ID, as in the following statement.

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