MAPPING PARAMETERS & VARIABLES (2022)

Mapping parameters and variables represent values in mappings and mapplets.

When we use a mapping parameter or variable in a mapping, first we declare the mapping parameter or variable for use in each mapplet or mapping. Then, we define a value for the mapping parameter or variable before we run the session.

MAPPING PARAMETERS

  • A mapping parameter represents a constant value that we can define before running a session.
  • A mapping parameter retains the same value throughout the entire session.

Example: When we want to extract records of a particular month during ETL process, we will create a Mapping Parameter of data type and use it in query to compare it with the timestamp field in SQL override.

  • After we create a parameter, it appears in the Expression Editor.
  • We can then use the parameter in any expression in the mapplet or mapping.
  • We can also use parameters in a source qualifier filter, user-defined join, or extract override, and in the Expression Editor of reusable transformations.

MAPPING VARIABLES

  • Unlike mapping parameters, mapping variables are values that can change between sessions.
  • The Integration Service saves the latest value of a mapping variable to the repository at the end of each successful session.
  • We can override a saved value with the parameter file.
  • We can also clear all saved values for the session in the Workflow Manager.

We might use a mapping variable to perform an incremental read of the source. For example, we have a source table containing time stamped transactions and we want to evaluate the transactions on a daily basis. Instead of manually entering a session override to filter source data each time we run the session, we can create a mapping variable, $$IncludeDateTime. In the source qualifier, create a filter to read only rows whose transaction date equals $$IncludeDateTime, such as:

TIMESTAMP = $$IncludeDateTime

In the mapping, use a variable function to set the variable value to increment one day each time the session runs. If we set the initial value of $$IncludeDateTime to 8/1/2004, the first time the Integration Service runs the session, it reads only rows dated 8/1/2004. During the session, the Integration Service sets $$IncludeDateTime to 8/2/2004. It saves 8/2/2004 to the repository at the end of the session. The next time it runs the session, it reads only rows from August 2, 2004.

Used in following transformations:

  • Expression
  • Filter
  • Router
  • Update Strategy

Initial and Default Value:

When we declare a mapping parameter or variable in a mapping or a mapplet, we can enter an initial value. When the Integration Service needs an initial value, and we did not declare an initial value for the parameter or variable, the Integration Service uses a default value based on the data type of the parameter or variable.

Data ->Default Value

Numeric ->0

String ->Empty String

Date time ->1/1/1

(Video) Mapping Variables & Parameter in Informatica, Powercenter

Variable Values: Start value and current value of a mapping variable

Start Value:

The start value is the value of the variable at the start of the session. The Integration Service looks for the start value in the following order:

  1. Value in parameter file
  2. Value saved in the repository
  3. Initial value
  4. Default value

Current Value:

The current value is the value of the variable as the session progresses. When a session starts, the current value of a variable is the same as the start value. The final current value for a variable is saved to the repository at the end of a successful session. When a session fails to complete, the Integration Service does not update the value of the variable in the repository.

Note: If a variable function is not used to calculate the current value of a mapping variable, the start value of the variable is saved to the repository.

Variable Data type and Aggregation Type When we declare a mapping variable in a mapping, we need to configure the Data type and aggregation type for the variable. The IS uses the aggregate type of a Mapping variable to determine the final current value of the mapping variable.

Aggregation types are:

  • Count: Integer and small integer data types are valid only.
  • Max: All transformation data types except binary data type are valid.
  • Min: All transformation data types except binary data type are valid.

Variable Functions

Variable functions determine how the Integration Service calculates the current value of a mapping variable in a pipeline.

SetMaxVariable: Sets the variable to the maximum value of a group of values. It ignores rows marked for update, delete, or reject. Aggregation type set to Max.

SetMinVariable: Sets the variable to the minimum value of a group of values. It ignores rows marked for update, delete, or reject. Aggregation type set to Min.

SetCountVariable: Increments the variable value by one. It adds one to the variable value when a row is marked for insertion, and subtracts one when the row is Marked for deletion. It ignores rows marked for update or reject. Aggregation type set to Count.

SetVariable: Sets the variable to the configured value. At the end of a session, it compares the final current value of the variable to the start value of the variable. Based on the aggregate type of the variable, it saves a final value to the repository.

Creating Mapping Parameters and Variables

(Video) #Informatica #Mapping Variables, Parameter Tutorial - Part 1 -Parameter and Variables in Informatica

  1. Open the folder where we want to create parameter or variable.
  2. In the Mapping Designer, click Mappings > Parameters and Variables. -or- In the Mapplet Designer, click Mapplet > Parameters and Variables.
  3. Click the add button.
  4. Enter name. Do not remove $$ from name.
  5. Select Type and Data type. Select Aggregation type for mapping variables.
  6. Give Initial Value. Click ok.

Example: Use of Mapping of Mapping Parameters and Variables

  • EMP will be source table.
  • Create a target table MP_MV_EXAMPLE having columns: EMPNO, ENAME, DEPTNO, TOTAL_SAL, MAX_VAR, MIN_VAR, COUNT_VAR and SET_VAR.
  • TOTAL_SAL = SAL+ COMM + $$BONUS (Bonus is mapping parameter that changes every month)
  • SET_VAR: We will be added one month to the HIREDATE of every employee.
  • Create shortcuts as necessary.

Creating Mapping

  1. Open folder where we want to create the mapping.
  2. Click Tools -> Mapping Designer.
  3. Click Mapping-> Create-> Give name. Ex: m_mp_mv_example
  4. Drag EMP and target table.
  5. Transformation -> Create -> Select Expression for list -> Create –> Done.
  6. Drag EMPNO, ENAME, HIREDATE, SAL, COMM and DEPTNO to Expression.
  7. Create Parameter $$Bonus and Give initial value as 200.
  8. Create variable $$var_max of MAX aggregation type and initial value 1500.
  9. Create variable $$var_min of MIN aggregation type and initial value 1500.
  10. Create variable $$var_count of COUNT aggregation type and initial value 0. COUNT is visible when datatype is INT or SMALLINT.
  11. Create variable $$var_set of MAX aggregation type.

MAPPING PARAMETERS & VARIABLES (1)

12. Create 5 output ports out_ TOTAL_SAL, out_MAX_VAR, out_MIN_VAR,

out_COUNT_VAR and out_SET_VAR.

13. Open expression editor for TOTAL_SAL. Do the same as we did earlier for SAL+ COMM. To add $$BONUS to it, select variable tab and select the parameter from mapping parameter. SAL + COMM + $$Bonus

14. Open Expression editor for out_max_var.

15. Select the variable function SETMAXVARIABLE from left side pane. Select

$$var_max from variable tab and SAL from ports tab as shown below.SETMAXVARIABLE($$var_max,SAL)

MAPPING PARAMETERS & VARIABLES (2)

17. Open Expression editor for out_min_var and write the following expression:

SETMINVARIABLE($$var_min,SAL). Validate the expression.

18. Open Expression editor for out_count_var and write the following expression:

SETCOUNTVARIABLE($$var_count). Validate the expression.

19. Open Expression editor for out_set_var and write the following expression:

(Video) Informatica : Mapping Parameters & Variables (Theory)

SETVARIABLE($$var_set,ADD_TO_DATE(HIREDATE,'MM',1)). Validate.

20. Click OK. Expression Transformation below:

MAPPING PARAMETERS & VARIABLES (3)

21. Link all ports from expression to target and Validate Mapping and Save it.

22. See mapping picture on next page.

MAPPING PARAMETERS & VARIABLES (4)

PARAMETER FILE

  • A parameter file is a list of parameters and associated values for a workflow, worklet, or session.
  • Parameter files provide flexibility to change these variables each time we run a workflow or session.
  • We can create multiple parameter files and change the file we use for a session or workflow. We can create a parameter file using a text editor such as WordPad or Notepad.
  • Enter the parameter file name and directory in the workflow or session properties.

A parameter file contains the following types of parameters and variables:

  • Workflow variable: References values and records information in a workflow.
  • Worklet variable: References values and records information in a worklet. Use predefined worklet variables in a parent workflow, but we cannot use workflow variables from the parent workflow in a worklet.
  • Session parameter: Defines a value that can change from session to session, such as a database connection or file name.
  • Mapping parameter and Mapping variable

USING A PARAMETER FILE

Parameter files contain several sections preceded by a heading. The heading identifies the Integration Service, Integration Service process, workflow, worklet, or session to which we want to assign parameters or variables.

  • Make session and workflow.
  • Give connection information for source and target table.
  • Run workflow and see result.

MAPPING PARAMETERS & VARIABLES (5)

Sample Parameter File for Our example:

In the parameter file, folder and session names are case sensitive.

Create a text file in notepad with name Para_File.txt

[Practice.ST:s_m_MP_MV_Example]

(Video) #Informatica #Mapping Variables Tutorial - Part 26 || Informatica Full #Video #Course

$$Bonus=1000

$$var_max=500

$$var_min=1200

$$var_count=0

CONFIGURING PARAMTER FILE

We can specify the parameter file name and directory in the workflow or session properties.

To enter a parameter file in the workflow properties:

1. Open a Workflow in the Workflow Manager.

2. Click Workflows > Edit.

3. Click the Properties tab.

4. Enter the parameter directory and name in the Parameter Filename field.

5. Click OK.

To enter a parameter file in the session properties:

1. Open a session in the Workflow Manager.

2. Click the Properties tab and open the General Options settings.

(Video) Mapping Parameters And Variables In Informatica

3. Enter the parameter directory and name in the Parameter Filename field.

4. Example: D:\Files\Para_File.txt or $PMSourceFileDir\Para_File.txt

5. Click OK.

FAQs

What is the difference between mapping variables and mapping parameters? ›

Unlike a mapping parameter, a mapping variable represents a value that can change through the session. The Integration Service saves the value of a mapping variable to the repository at the end of each successful session run and uses that value the next time you run the session.

What are the parameters of a variable? ›

A parameter is a named variable passed into a function. Parameter variables are used to import arguments into functions. Note the difference between parameters and arguments: Function parameters are the names listed in the function's definition.

What is variable mapping? ›

A variable map is a definition of how to construct a property set in a given situation and of which changes to save. Each variable has one or more variable sources that define how to retrieve the variable value in a given mode (such as Quote, Order, or Any).

Can parameters be used as variables? ›

Overview. A parameter is a special kind of variable used in a function to refer to one of the pieces of data provided as input to the function.

What is $$ $$$ in Informatica? ›

$$$ refers System Parameters like $$$SessStartTime. Actually $ means internal Parameter/Variable (such as $DBConnection prefix or $PMSessionLogDir) whereas $$ are used for user-defined parameters or variables (which could be defined at mapping or workflow/worklet level).

How do you use map parameters? ›

Using parameters in a mapping
  1. In the mapping, select the Source transformation.
  2. On the. Source. ...
  3. Add a Filter transformation.
  4. On the. Filter. ...
  5. Configure the Target transformation.
  6. Select the Source transformation.
  7. On the. Source.

What is a parameter example? ›

A parameter is used to describe the entire population being studied. For example, we want to know the average length of a butterfly. This is a parameter because it is states something about the entire population of butterflies.

What do you mean by parameters? ›

A parameter is a limit. In mathematics a parameter is a constant in an equation, but parameter isn't just for math anymore: now any system can have parameters that define its operation. You can set parameters for your class debate.

How do you find parameters? ›

When values are assigned to the parameters, such as the slope m = 2 and the y-intercept b = 3, and substitution is made, the resulting equation, y = 2x + 3, is that of a specific straight line and is no longer parametric. In the set of equations x = 2t + 1 and y = t2 + 2, t is called the parameter.

What are parameters and variables in Informatica? ›

ParameterName. is a user-defined mapping parameter. Mapping variables. Define values that can change during a session. The Integration Service saves the value of a mapping variable to the repository at the end of each successful session run and uses that value the next time you run the session.

How do you create a mapping parameter in Informatica? ›

In a reusable transformation, create a parameter for a property in the transformation or for a variable in the Expression Editor. Add the transformation to a mapping or to a mapplet. tab, choose how to set the parameter value in the mapping or the mapplet. Expose the transformation parameter as a mapping parameter.

How do you assign a mapping variable in Informatica? ›

Name of the mapping variable you want to set. Use with mapping variables with Max/Min aggregation type. The value you want to set the current value of the variable to. You can enter any valid transformation expression that evaluates to a datatype compatible with the datatype of the variable.

What are different types of parameters? ›

Supported parameter types are string, integer, Boolean, and array.

Why do we use parameters? ›

Parameters allow us to pass information or instructions into functions and procedures . They are useful for numerical information such as stating the size of an object. Parameters are the names of the information that we want to use in a function or procedure. The values passed in are called arguments.

Is a parameter a constant or a variable? ›

A parameter is a quantity that influences the output or behavior of a mathematical object but is viewed as being held constant.

Can you use the mapping parameters or variables created in one mapping into another mapping? ›

Can we use the mapping parameters or variables created in one mapping into another mapping? NO. We can use the mapping parameters or variables only in the transformations of the same mapping or mapplet in which we have created the mapping parameters or variables.

How do you use mapping parameters in expression transformation? ›

To use User Parameter in Expression do as following :
  1. Open Informatica Cloud and click Design > Mappings.
  2. Create an Input Parameter in the Mapping eg: Userpara.
  3. Go to the Expression transformation -> Expression.
  4. Create a Field and give the Input parameter in the Expression section eg: NewString = $Userpara$​
May 19, 2022

What is parameter Informatica? ›

Informatica parameter file is a text file which contains Parameter values and Variable values for mapping, session and workflows. It keeps the properties of workflows, sessions and mappings. 1) Data processing without changing the code in Prod environment.

Can we use mapping parameter in mapplet? ›

We can use the mapping parameters or variables in the transformations of the same mapping or mapplet.

Videos

1. Mapping Parameter & Variable with Parameter File
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2. "Informatica Mapping Parameter and Variables" Basic Concepts
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3. How to use the value of a mapping variable from parameter file
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4. Informatica Tutorial for Beginners Mapping Parameters and Variables in Informatica Training Videos
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5. 04 Parameters & variables: Tips for Informatica PowerCenter Specialist Certification!
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