System functions return special information from the database. The system functions are:
col_length
col_name
curunreservedpgs
data_pgs
datalength
db_id
db_name
host_id
host_name
index_col
isnull
lct_admin
mut_excl_roles
object_id
object_name
proc_role
ptn_data_pgs
reserved_pgs
role_contain
role_id
role_name
rowcnt
show_role
suser_id
suser_name
tsequal
used_pgs
user
user_id
user_name
valid_name
valid_user
The system functions can be used in a select list, in a where clause, and anywhere an expression is allowed.
When the argument to a system function is optional, the current database, host computer, server user, or database user is assumed.
