Limitations on use of strings

Some varying-length string data types cannot be referenced in certain contexts.

The following varying-length string data types cannot be referenced in certain contexts:

Table 1. Contexts for limitations on use of varying-length strings
Context of usage LOB (CLOB, DBCLOB, or BLOB)
Start of changeThe CREATE INDEX statementEnd of change Start of changeNot allowedEnd of change
The definition of primary, unique, and foreign keys Not allowed
Parameters of built-in functions Some functions that allow varying-length character strings, varying-length graphic strings, or both types of strings as input arguments do not support CLOB or DBCLOB strings, or both as input. See the description of the individual functions in Built-in functions for the data types that are allowed as input to each function.