| IS [NOT] DISTINCT FROM | Compares two expressions to determine whether they have the same or different values. NULLs are considered as comparable values. |
| ISDATE | Returns true if the input expression can be cast to a date. |
| IS [NOT] FALSE | Tests whether the input expression is either false or not false. If true in either case, returns a value of true. Alias for the function ISFALSE/ISNOTFALSE. |
| IS [NOT] NULL | Determines if an expression is NULL or not NULL. Alias for the function ISNULL/ISNOTNULL. |
| ISNUMERIC | Determines whether an expression is a valid numeric type (DECIMAL, DOUBLE, INT, BIGINT, VARBINARY). |
| IS [NOT] TRUE | Tests whether the input expression is either true or not true. If true in either case, returns a value of true. Alias for the function ISTRUE/ISNOTTRUE. |
| IS_MEMBER | Returns whether the current user is a member of the specified role. This function cannot be used in a reflection. |
| IS_SUBSTR | Returns true if a string is contained within another string. The comparison is case-sensitive. |