Expression Masking
Expression masking applies an expression to a column to mask or change data. Mask all data types with expression masking.
To configure expression masking, you create an expression in the Expression Builder.
Select column, functions, variables, and operators to build expressions. The expression can reference input columns and output columns.
In expression masking, you can append additional data to the source column data. For example, you want to mask the first names. The source has the FirstName column and you want to concatenate the values in the FirstName column with the string ABC. When you configure the data masking rule, select the FirstName column and enter the following expression in the expression editor.
CONCAT(FirstName,'ABC')
When you configure expression masking for a column, the column name appears as the expression by default.
Select functions, columns, variables, and operators from the point-and-click interface to minimize errors when you build expressions.
When you create an expression, verify that the expression returns a value that matches the column data type. The PowerCenter Integration Service returns zero if the return value does not match a numeric column. It returns NULL if the return value does not match a string column.
You cannot perform expression masking with repeatable output for Hadoop data sources.
For information about expression syntax, see the Informatica Transformation Language Reference.
Expression Masking Parameters
You can configure parameters for the expression masking technique.
The following table describes the parameters that you can configure for expression masking:
Parameter | Description |
|---|
Repeatable Output | Determines if the masked value should persist for a given column value. You must enter a seed value when you enable repeatable output. You cannot perform expression masking with repeatable output for Hadoop data sources. |
Alphanumeric Seed | The alphanumeric seed is a key that allows multiple data masking rules to generate the same masked values from the same source values. Define the same seed in each data masking rule that requires the same results for a column. The seed can be any text. |
Expression | Accepts PowerCenter expressions and performs a calculation based on values within a single row. |
Rules and Guidelines for Expression Masking
Use the following rules and guidelines for expression masking:
- •You cannot use the output from an expression as input to another expression. If you manually add the output column name to the expression, you might get unexpected results.
- •Select functions, columns, variables, and operators from the point-and-click interface to minimize errors when you build expressions.
- •If the data masking rule is configured for repeatable masking, specify the storage table in the data masking plan. If the storage table does not exist, the data masking operation fails.