Multivalued (Array Type) Attributes - Parallel Transporter

Multivalued (Array Type) Attributes

Teradata PT allows specification of multiple values for a few operator attributes. Array attribute values can be specified as part of:

A DEFINE OPERATOR statement

A reference to an operator in an APPLY statement

Available array attributes are shown in the following table:

Attribute	Operator
ErrorList	DDL
TargetTable ErrorTable1 ErrorTable2	Load
TargetTable WorkTable ErrorTable1 ErrorTable2	Update
TraceLevel	DDL Export Load ODBC OS Command SQL Inserter SQL Selector Stream Update

The following examples show how specification of an array value for an attribute would appear in a DEFINE OPERATOR statement or an APPLY statement:

VARCHAR ARRAY TraceLevel = [ 'CLI', 'OPER' ]

VARCHAR TraceLevel = [ 'CLI', 'OPER' ]

TraceLevel = [ 'CLI', 'OPER' ]

The syntax for using one or more array attributes in a DEFINE statement is shown in “Specification of Operator Attributes” on page 60.

Observe the following additional guidelines for use of array attributes.

The Teradata PT compiler ensures that array attributes are assigned array-type (multiple) values and vice versa; multiple values are assigned only to array attributes.

Array values can be assigned in a series as shown in the following examples:

VARCHAR ARRAY TargetTable = ['table1', 'table2', …, 'tableN']

VARCHAR TargetTable = ['table1', 'table2', …, 'tableN']

TargetTable = ['table1', 'table2', …, 'tableN']

Using the ARRAY keyword in assigning an array value is optional.

An array value containing a single member (for example, ['x'] or [2]) is still considered a valid array value. In this case, the array dimension is 1. However, even this single value must be specified through array notation, that is to say, enclosed in [ ].

To omit some of the values for the array attribute, for example, to assign a first and a third value, but not the second, you can do the following: specify a value of NULL. Following is an example of assigning certain attribute values while omitting others.

specify a value of NULL, as follows:

VARCHAR FILE_NAMES = ['/first', NULL, '/third']

specify the omitted value with commas, as follows:

VARCHAR FILE_NAMES = ['/first', , '/third']

Following example shows an array attribute value assigned as part of a SELECT statement:

   SELECT * FROM OPERATOR (reader ATTR (FILE_NAMES = ['/first', NULL,'/   third'], MODE = 'read')

Note: Use of VARCHAR and INTEGER is optional when specifying an array attribute value. For detailed information on using VARCHAR and INTEGER, see “Syntax Rules” on page 44.

For details about how to use array attributes for a particular operator, see the chapter on that operator in Teradata Parallel Transporter Reference.