Teradata Parallel Data Pump

Chapter 3: Teradata TPump Commands
FIELD
Syntax Element
fieldexpr
DROP
KEY
Description
Concatenation of two or more items, either:
• fields
• character constants
• string constants
or a combination of these, as in:
fieldname1||'C'||fieldname2||'STRING'||fieldname3...
The field names within a layout must be unique and the data type of the field
must be either CHAR or VARCHAR. Nested concatenations are not supported.
If all items of the fieldexpr are fixed character (for example, no VARCHARs), the
data type of the resulting field is CHAR(m), where “m” is the sum of the length
for each component item.
If at least one component of the fieldexpr is a VARCHAR, the data type of the
resulting field is VARCHAR(m), where “m” is the sum of the maximum length
for each component item.
When the character set of the job script is different from the client character set
used for the job (for example, on z/OS the job script must be in Teradata
EBCDIC when using the UTF8 client character set, or UTF-16 client character
set can be used with the job script in UTF8), Teradata TPump will translate the
character constants and the string constants specified in the expression from the
script character set form to the client character set form before concatenating
the constants with the specified fields.
Caution: When using the UTF8 client set on the mainframe, be sure to
examine the definition in International Character Set Support to
determine the code points of the special characters which might be
require. Different versions of EBCDIC do not always agree as to the
placement of these characters.
The mappings between Teradata EBCDIC and Unicode can be
referred to in Appendix E of International Character Set Support.
Characters present in the specified position(s) to be dropped from the specified
fieldname, which must be of a character data type
Teradata TPump drops the specified characters and presents the field to
Teradata Database as a VARCHAR data type.
If two dropping actions are specified, they must not be identical.
If a FIELD command defines a fieldname in terms of two or more concatenated
fieldname fields, any specified DROP clause applies to the concatenated result,
not to the individual fieldname fields. But, because each fieldname must be
defined by its own previous FIELD command, a DROP clause can be specified
on these commands to apply to the individual fields.
Keyword, which, when added to the end of the FIELD command, specifies that
the field is part of the hash key for purposes of serialization, if the SERIALIZE
parameter on the BEGIN LOAD command is active.
The serialization feature is meaningful only when a primary key for the loaded
data is specified via this KEY option.
Teradata Parallel Data Pump Reference 135