Summary information |
|
|---|---|
Default value |
0 (off) |
Valid values |
0 (off), 1 (on) |
Status |
Dynamic |
Display level |
Comprehensive |
Required role |
System Administrator |
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. 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 Sybase-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. Always use begin transaction when modifying a system table to protect against errors that could corrupt your databases. 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 are always able to 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, it is best to set this parameter to on only in highly controlled situations. To guarantee that no other users can access Adaptive Server while the system tables can be directly updated, restart Adaptive Server in single-user mode. For details, see startserver and dataserver in the Utility Guide.
