Teradata Parallel Data Pump

Chapter 3: Teradata TPump Commands
DML
Syntax Element
ArraySupport
ON/OFF
Description
“ArraySupport ON|OFF” option to the .BEGIN LOAD command and the
.DML command
When “ArraySupport ON” is specified in the .BEGIN LOAD command, the
.DML commands enclosed in .BEGIN LOAD and .END LOAD command pair
will use the ArraySupport feature for its DML statement, unless “ArraySupport
OFF” is specified for the .DML command. The default value of ArraySupport
for the .BEGIN LOAD command is OFF.
When “ArraySupport ON|OFF” is not specified with the .DML command, the
default value for ArraySupport for that .DML command is the effective setting
of ArraySupport in the .BEGIN LOAD command where the .DML command
resides. When “ArraySupport ON|OFF” is specified at the .DML command,
the specified value overrides the default setting determined by the .BEGIN
LOAD command.
When a .DML command is using the ArraySupport feature, it must contain
one and only one DML statement and the session partition that the .DML
command references needs to be used exclusively by this .DML command.
If the DML statement is an UPSERT-type statement, it can be specified as a
pair of INSERT/UPDATE statements with DO INSERT FOR MISSING
UPDATE clause. Teradata TPump will create its equivalent form of UPDATE
… ELSE INSERT …, example Atomic Upsert, and use it as the actual DML
statement. Or an UPDATE … ELSE INSERT … statement can be directly
specified with DO INSERT FOR MISSING UPDATE clause.
The non-atomic form of UPSERT is not supported by Teradata TPump Array
Support.
Usage Notes
The SQL EXECUTE command must be used between the BEGIN LOAD command and the
END LOAD command.
All INSERT, UPDATE, DELETE, and EXECUTE statements specified in the Teradata TPump
script should fully specify the primary index of the referenced table to prevent the generation
of table-level locks.
A maximum of 2430 DML statements may be packed into a request; the default is
20 statements.
Teradata TPump assumes that row hash locking is used by INSERT, UPDATE, DELETE, and
EXECUTE statements. If row hash locking is not used, Teradata TPump will run anyway, but
may encounter trouble because table-level locking will cause each statement to block.
In addition, Teradata TPump does not support UPDATE or EXECUTE statements that
modify the primary index of the target table. Teradata TPump performs no checking to
prevent the script author from creating DML that requests unreasonable updates, except that
Teradata TPump will not use Atomic UPSERT if the UPDATE portion of the UPSERT
specifies an unreasonable update. This restriction is imposed by Teradata Database.
IGNORE DUPLICATE ROWS does not apply if there are ANY unique indexes in the row.
118 Teradata Parallel Data Pump Reference