External Representation
Whenever a client application talks to Vantage, it indicates its character set (form-of-use for character data). Vantage returns all character data to the application in that form.
Whenever multibyte characters are involved, their representation has the length (n-2)/2 multibyte characters exclusive of the preceding Shift-Out and following Shift-In characters.
The following table lists the client representations for the CLOB data type. Determining the application definitions and client data types is the responsibility of the application programmer.
Define the length of the CLOB string as k, where 0 ≤ k ≤ n.
| Client CPU Architecture | Client Internal Data Format |
|---|---|
| IBM mainframe | Eight byte (most significant byte first) length count k followed by k bytes of EBCDIC character data for a total of k+8 bytes. |
|
Eight byte (most significant byte first) length count k followed by k bytes of ASCII character data for a total of k+8 bytes. |
| Intel | Eight byte (least significant byte first) length count k followed by k bytes of ASCII character data for a total of k+8 bytes. |
Restrictions
A table can have a maximum of 32 LOB columns.
Queue tables cannot have CLOB columns.
A LOB column cannot be a component of an index. Because of this restriction, a table must define at least one non-LOB column.
- LATIN
- UNICODE
Functions That Operate on CLOBs
- CHARACTERS/CHARS/CHAR
- MCHARACTERS
- CHARACTER_LENGTH
- TRANSLATE and TRANSLATE_CHK
- SUBSTRING/SUBSTR
- Concatenation operator (||)
- TYPE
- Explicit data type conversion (CAST and Teradata conversion syntax)
- User-defined functions (UDFs)
- Stored procedures
- External stored procedures