Informatica 8.6 Enhancements for Developers – 1

Informatica has released its latest version 8.6 covering all the hot fixes it released for the prior version 8.5 and including few new features. Since version 8, a Unified Admin Console has been designed for managing Integration and Repository services. These were discussed in earlier Blogs.

What does PowerCenter 8.6 bring new for the developers? Let us discuss PowerCenter 8.6 Client enhancements which will be useful to the developers.

1. Creating Targets from Transformations

We can create targets based on transformations in the workspace or navigator.

To create a target,

1. Right-click the transformation in the workspace and select the Create and Add Target option.

2. Alternatively, we can drag and drop the transformation in the Target Designer.

The target that is created has the same port definitions as the transformation from which it was created. We can edit the target definitions later. In addition, the target type is the same as that of the repository used.

2. Invalid/Invalidated renamed

In PowerCenter 7, the two states of objects were known as Invalid and Invalidated.

The exact meaning of these states is as follows:

Invalid – an object will not run,

Invalidated – an object may be invalid or may not run.

The difference between the two terms was not very clear. Therefore, to avoid any confusion, in PowerCenter 8.6, the two states have been renamed as Invalid and Impacted. While the Invalid state still implies that an object will not run, Impacted means that an object is affected by a change, and therefore, may not run.

Apart from the naming convention the icons are also changed in PowerCenter 8.

3. Propagating Port Descriptions

In the Designer, in addition to the other properties of port propagation, we can edit a port description and propagate the description to other transformations in the mapping.

4. Environment SQL Enhancements

In PowerCenter 8, environment SQL can be used to execute an SQL statement at the beginning of each transaction. The Integration Service executes transaction environment SQL at the beginning of each transaction. Environment SQL can still be used to execute an SQL statement at each connection to the database.

Use SQL commands that depend upon a transaction being opened during the entire read or write process. For example, the following SQL command modifies how the session handles characters:

ALTER SESSION SET NLS_LENGTH_SEMANTICS=CHAR

5. Flat File Enhancements

PowerCenter 8 includes enhancements for handling flat files. Some of these improve performance.

Flat files can now use Integer or Double data types.

In addition, target partitions can be merged. The flat file target merge options include:

Read More about Informatica 8.6

Informatica PowerCenter 8x Key Concepts -3

dministration Console

The Administration Console is a web application that we use to administer the PowerCenter domain and PowerCenter security. There are two pages in the console, Domain Page & Security Page.
We can do the following In Domain Page:

o Create & manage application services like Integration Service and Repository Service

o Create and manage nodes, licenses and folders

o Restart and shutdown nodes

o View log events

o Other domain management tasks like applying licenses and managing grids and resources

We can do the following in Security Page:

o Create, edit and delete native users and groups

o Configure a connection to an LDAP directory service. Import users and groups from the LDAP directory service

o Create, edit and delete Roles (Roles are collections of privileges)

o Assign roles and privileges to users and groups

o Create, edit, and delete operating system profiles. An operating system profile is a level of security that the Integration Services uses to run workflows

4. PowerCenter Client

Designer, Workflow Manager, Workflow Monitor, Repository Manager & Data Stencil are five client tools that are used to design mappings, Mapplets, create sessions to load data and manage repository.

Mapping is an ETL code pictorially depicting logical data flow from source to target involving transformations of the data. Designer is the tool to create mappings

Designer has five window panes, Source Analyzer, Warehouse Designer, Transformation Developer, Mapping Designer and Mapplet Designer.

Source Analyzer:

Allows us to import Source table metadata from Relational databases, flat files, XML and COBOL files. We can only import the source definition in the source Analyzer and not the source data itself is to be understood. Source Analyzer also allows us to define our own Source data definition.

Warehouse Designer:

Allows us to import target table definitions which could be Relational databases, flat files, XML and COBOL files. We can also create target definitions manually and can group them into folders. There is an option to create the tables physically in the database that we do not have in source analyzer. Warehouse designer doesn’t allow creating two tables with same name even if the columns names under them vary or they are from different databases/schemas.

Transformation Developer:

Transformations like Filters, Lookups, Expressions etc that have scope to be re-used are developed in this pane. Alternatively Transformations developed in Mapping Designer can also be reused by checking the option‘re-use’ and by that it would be displayed under Transformation Developer folders.

Mapping Designer:

This is the place where we actually depict our ETL process; we bring in source definitions, target definitions, transformations like filter, lookup, aggregate and develop a logical ETL program. In this place it is only a logical program because the actual data load can be done only by creating a session and workflow.

Mapplet Designer:

We create a set of transformations to be used and re-used across mappings.

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Few tips related to Informatica 8.x environment

Let us discuss some special scenarios that we might face in Informatica 8.x environments.

A. In Informatica 8.x, multiple integration services can be enabled under one node. In case if there is a need to determine the process associated with an Integration service or Repository service, then it can be done as follows.

If there are multiple Integration Services enabled in a node, there are multiple pmserver processes running on the same machine. In PowerCenter 8.x, it is not possible to differentiate between the processes and correlate it to a particular Integration Service, unlike in 7.x where every pmserver process is associated with a specific pmserver.cfg file. Likewise, if there are multiple Repository Services enabled in a node, there are multiple pmrepagent processes running on the same machine. In PowerCenter 8.x, it is not possible to differentiate between the processes and correlate it to a particular Integration Service.

To do these in 8.x do the following:

1.      Log on to the Administration Console

2.      Click on Logs > Display Settings.

3.      Add Process to the list of columns to be displayed in the Log Viewer.

4.      Refresh the log display.

5.      Use the PID from this column to identify the process as follows:

UNIX:

Run the following command:

ps –ef grep pid

Where pid is the process ID of the service process.

Windows:

1. 1. Run task manager.
   2. Select the Processes tab.

Scroll to the value in the PID column that is displayed in the PowerCenter Administration Console.

B. Sometimes, the PowerCenter Administration Console URL is inaccessible from some machines even when the Informatica services are running. The following error is displayed on the browser:

“The page cannot be displayed”

The reason for this is due to an invalid or missing configuration in the hosts file on the client machine.

To resolve this error, do the following:

1. Edit the hosts file located in the windows/system32/drivers/etc folder on the server from where the Administration Console is being accessed.
2. Add the host IP address and the host name (for the host where the PowerCenter services are installed).

Example

10.1.2.10 ha420f3

1. Launch the Administration Console and access the login page by typing the URL: http://<host>:<port>/adminconsole in the browser address bar.

It should be noted that the host name in the URL matches the host entry in the hosts file.

Read More about Informatica 8.x

Informatica and Stored Procedures

A. Described below is a scenario where the requirement is to have a stored procedure that returns a cursor as a source.By and large PowerCenter does not support a stored procedure that returns a cursor as a source. The workaround for this is1. The procedure that will load the data to a new table:

CREATE OR REPLACE procedure load (p_initial_date in date, p_final_Date in date) as

str_load varchar2 (500);
str_clean varchar2 (500);
begin
str_clean:= ‘DELETE FROM EMP’;
str_load:= ‘INSERT INTO EMP select * from EMPLOYEE where DOJ between trunc

(p_initial_date) and trunc (p_final_Date) ‘;
execute immediate str_clean;
execute immediate str_load;
EXCEPTION
WHEN OTHERS
THEN
ROLLBACK;
end load;

2. Create the table that will receive the data from the procedure:

SQL> create table EMP as SELECT * from EMPLOYEE where 1 > 2;

3. Add a Store Procedure transformation to the PowerCenter mapping. This transformation will execute this new procedure called as LOAD on this example.

4. Set the run method to be Source Pre Load, to be executed before read the source table.

5. Import the EMP table as a Source Definition. This table will be populated by the new Store Procedure.

If the original store procedure is used by the customer application and you can’t change the source code, you can create a new store procedure that call the original one (without inserting into a table), and execute the insert on the new table executing a loop on the returned cursor.

B. Given below is a situation where you wanted to pass a mapping variable to a stored procedure transformation (it can either be connected or unconnected).

Connected Stored Procedure

The parameters that are passed to a connected Stored Procedure have to be linked from another transformation.
Given below are the steps to pass mapping variable to a connected Stored Procedure transformation:

1. Create an Expression transformation.
2. Create an output port in the Expression transformation with the following expression:

$$mapping_variable

This sets the value of this output port to the mapping variable.

1. Link this output port to the Stored Procedure transformation.

Unconnected Stored Procedure

For unconnected Stored Procedure transformations you can use the mapping variable in the expression calling the stored procedure.
Follow the steps below to pass mapping variable to a unconnected Stored Procedure transformation:

1. Create an Expression transformation.
2. Create an output port in the Expression transformation with the following expression:

: SP.GET_NAME_FROM_ID ($$mapping_variable, PROC_RESULT)

In case if you are attempting to use a mapping variable to store the output value of the stored procedure, the session will fail with the below error.

“TE_7002 Transformation Parse Fatal Error; transformation stopped: invalid function reference. Failed to Initialize Server Transformation.”

To resolve the issue replace the mapping variable with the PROC_RESULT system variable.

Example:

Incorrect, using a mapping variable:

:SP.PROCEDURE(FIELD1, $$mapping_variable)

Correct, using the PROC_RESULT system variable:

:SP.PROCEDURE(FIELD1,PROC_RESULT)

Or

:SP.PROCEDURE($$mapping_variable,PROC_RESULT)

The PROC_RESULT system variable assigns the stored procedure output to the port with this expression.

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Informatica PowerCenter 8x Key Concepts – 2

The PowerCenter Repository is one of best metadata storage among all ETL products. The repository is sufficiently normalized to store metadata at a very detail level; which in turn means the Updates to therepository are very quick and the overall Team-based Development is smooth. The repository data structure is also useful for the users to do analysis and reporting.

Accessibility to the repository through MX views and SDK kit extends the repositories capability from a simple storage of technical data to a database for analysis of the ETL metadata.

PowerCenter Repository is a collection of 355 tables which can be created on any major relational database. The kinds of information that are stored in the repository are,

1. Repository configuration details
2. Mappings
3. Workflows
4. User Security
5. Process Data of session runs

For a quick understanding,

When a user creates a folder, corresponding entries are made into table OPB_SUBJECT; attributes like folder name, owner id, type of the folder like shared or not are all stored.
When we create\import sources and define field names, datatypes etc in source analyzer entries are made into opb_src and OPB_SRC_FLD.
When target and related fields are created/imported from any database entries are made into tables like OPB_TARG and OPB_TARG_FLD.
Table OPB_MAPPING stores mapping attributes like Mapping Name, Folder Id, Valid status and mapping comments.
Table OPB_WIDGET stores attributes like widget type, widget name, comments etc. Widgets are nothing but the Transformations which Informatica internally calls them as Widgets.
Table OPB_SESSION stores configurations related to a session task and table OPB_CNX_ATTR stores information related to connection objects.
Table OPB_WFLOW_RUN stores process details like workflow name, workflow started time, workflow completed time, server node it ran etc.
REP_ALL_SOURCES, REP_ALL_TARGETS and REP_ALL_MAPPINGS are few of the many views created over these tables.

PowerCenter applications access the PowerCenter repository through the Repository Service. The Repository Service protects metadata in the repository by managing repository connections and using object-locking to ensure object consistency.

We can create a repository as global or local. We can go for‘global’ to store common objects that multiple developers can use through shortcuts and go for local repository to perform of development mappings and workflows. From a local repository, we can create shortcuts to objects in shared folders in the global repository. PowerCenter supports versioning. A versioned repository can store multiple versions of an object.

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