In an Informatica Expression transformation, variable ports retain their value from the previously processed row. The Integration Service evaluates ports in a specific order: it uses the previous row's variable port value to calculate the current row's output ports, and then it calculates the current row's variable port value for use in the next row.

For row 1, STATE is 'CA'. The variable port vPREVIOUSSTATE is set to 'CA'. For row 2, the output port PREVIOUSSTATE is evaluated first, using the value of vPREVIOUSSTATE from row 1, which is 'CA'.

A. STATE would refer to the value of the STATE port for the current row (row 2), not the value from the previous row.

C. The variable port is not NULL because it was assigned the value 'CA' during the processing of the first row.

D. A default value is used only when a variable port's expression evaluates to NULL on the first row. Here, a non-NULL value was assigned.

1. Informatica PowerCenter 10.5

Developer Guide

Chapter 11: "Expression Transformation"

Section: "Variable Ports".

Reference Detail: This section states

"When you create a variable port in an Expression transformation

the Integration Service uses the value of the variable from the previous row to calculate the current row." This directly supports the logic that the value from row 1 ('CA') is used for the output in row 2.

2. Informatica PowerCenter 10.5

Transformation Language Reference

Chapter 10: "Variables"

Section: "Using Variables in Expressions".

Reference Detail: This section explains the evaluation order: "For each row

the Integration Service evaluates expressions in the following order: 1. Input port expressions. 2. Variable port expressions that do not depend on other variable ports. ... The Integration Service uses the result of the variable port from the previous row in the output port expression for the current row." This confirms the mechanism described in the explanation.