Table 3-10 describes new global variables for 12.5.1.
Global variable  | 
Definition  | 
|---|---|
@@datefirst  | 
Set using set datefirst n where n is a value between 1 and 7. Returns the current value of @@datefirst, indicating the specified first day of each week (1 for Sunday, 2 for Monday, and so on), expressed as tinyint. The default value in Adaptive Server is 1, Sunday (based on the us_language default).  | 
@@lock_timeout  | 
Set using set lock wait n. Returns the current lock_timeout setting, in milliseconds. @@lock_timeout returns the value of n. The default value is no timeout. If no set lock wait n is executed at the beginning of the session, @@lock_timeout returns -1.  | 
@@max_precision  | 
Returns the precision level used by decimal and numeric datatypes set by the server. This value is a fixed constant of 38.  | 
@@tempdbid  | 
Returns a valid temporary database ID of the session’s assigned temporary database.  |