Workflow variables in Informatica PowerCenter are dynamic values that can be defined and used within a workflow. They allow you to store and manipulate data during workflow execution, enabling you to create more flexible and dynamic workflows.
Here's a breakdown:
Core Concept :
- Workflow variables are similar to mapping variables, but they operate at the workflow level rather than the mapping level.
- They can store various data types, such as strings, numbers, and dates.
- They can be assigned values, updated, and used in different tasks within a workflow.
Key Uses and Functionality :
- Passing Values Between Tasks:
- Workflow variables can be used to pass data between different tasks in a workflow.
- For example, you can store a file name in a workflow variable and then use it in a subsequent file transfer task.
- Controlling Workflow Execution:
- Workflow variables can be used in conditional expressions to control the flow of a workflow.
- For example, you can use a workflow variable to track the success or failure of a task and then use it to determine which task to execute next.
- Storing Runtime Information:
- Workflow variables can be used to store runtime information, such as timestamps, counters, and error codes.
- This information can be used for logging, auditing, and debugging.
- Parameterization:
- Workflow variables can be used to parameterize workflows, making them more reusable and adaptable.
- You can set the values of workflow variables at runtime, allowing you to customize the behavior of the workflow.
- Tracking counts:
- Workflow variables are very useful for counting the number of rows processed in a workflow.
- Error Handling:
- Workflow variables can be used to store error codes, or error messages that can be used later in the workflow, for notifications, or logging.
How They Are Used :
- Definition:
- You define workflow variables in the workflow designer, specifying their name, data type, and initial value.
- Assignment:
- You can assign values to workflow variables using various methods, such as:
- Task properties (e.g., post-session variables).
- Expression tasks.
- Assignment tasks.
- Usage:
- You can use workflow variables in various tasks, such as:
- Conditional expressions.
- Command tasks.
- Email tasks.
- Session tasks (through parameter files).
- Retrieval:
- Workflow variables can be accessed by using their name, within the workflow.
Example :
- You could use a workflow variable called "current_date" to store the current date and then use it in the file name of a target file.
- You could use a workflow variable called "error_count" to track the number of errors that occur during a workflow and then send an email notification if the error count exceeds a certain threshold.
