CLOB Data Type Usage Notes - Teradata VantageCloud Lake

External Representation

A client application talks to Vantage 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.
UTS RISC Motorola 68000 WE 32000	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. Therefore, a table must define at least one non-LOB column.

The CHARACTER SET clause can specify the following server character sets for a CLOB column:

LATIN
UNICODE

Functions That Operate on CLOBs

The following functions and operators support CLOB types:

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