allow updates to system tables

allow updates to system tables enables users with the system administrator role to make changes to the system tables and to create stored procedures that can modify system tables.

Summary Information
Default value	0 (off)
Valid values	0 (off), 1 (on)
Status	Dynamic
Display level	Comprehensive
Required role	System administrator
Configuration group	SQL Server Administration

A database administrator can update system tables in any tables that he or she owns if allow updates to system tables is enabled.

System tables include:

All SAP-supplied tables in the master database
All tables in user databases that begin with “sys” and that have an ID value in the sysobjects table of less than or equal to 100

Warning! Incorrect alteration of a system table can result in database corruption and loss of data. To protect against errors that might corrupt your databases, always use begin transaction when modifying a system table. Immediately after finishing your modifications, disable allow updates to system tables.

Stored procedures and triggers you create while allow updates to system tables is set on can update the system tables, even after the parameter has been set off. When you set allow updates to system tables to on, you create a “window of vulnerability,” a period of time during which users can alter system tables or create a stored procedure with which the system tables can be altered in the future.

Because the system tables are so critical, SAP suggests that you set this parameter to on only in highly controlled situations. To guarantee that no other users can access SAP ASE while the system tables can be directly updated, restart SAP ASE in single-user mode. For details, see startserver and dataserver in the Utility Guide.

Note: The server-wide configuration option allow updates to system tables takes precedence over the stored procedure settings for allow updates to system tables. If you do not enable allow updates to system tables at the server level, individual stored procedure settings determine whether you can modify system catalogs.