Here are the default result type and attributes for SUBSTR(string , n1 , n2) and SUBSTRING(string FROM n1 FOR n2):
If the string argument is a:
- BLOB, the result type is BLOB(n).
- Byte string other than BLOB, the result type is VARBYTE(n).
- CLOB, the result type is CLOB(n).
- Numeric or character string other than CLOB, the result type is VARCHAR(n).
In ANSI mode, the value of n for the resulting BLOB(n), VARBYTE(n), CLOB(n), or VARCHAR(n) is the same as the original string. In Teradata mode, the value of n for the result type depends on the number of characters or bytes in the resulting string. To get the data type of the resulting string, use the TYPE function.