Use sp_addthreshold to create free-space thresholds. Its syntax is:
sp_addthreshold dbname, segname, free_space, proc_name
The dbname must specify the name of the current database. The remaining parameters specify the segment whose free space is being monitored, the size of the threshold in database pages, and the name of a stored procedure.
When the amount of free space on the segment falls below the threshold, an internal Adaptive Server process executes the associated procedure. This process has the permissions of the user who created the threshold when he or she executed sp_addthreshold, less any permissions that have since been revoked.
Thresholds can execute a procedure in the same database, in another user database, in sybsystemprocs, or in master. They can also call a remote procedure on an Open Server. sp_addthreshold does not verify that the threshold procedure exists when you create the threshold.
