Update Strategy Transformation in
Informatica , is a
connected and active transformation.Update Strategy transformation let you insert, update , delete data from target Data also. It can also reject the incoming data depending upon your condition.
For example : when a customer is changing address , you can use this update strategy transformation to update data in your Customer Tables. In below article we will go through the properties of
Update Strategy Transformation. We will also discuss the
steps of adding /configuring Update Strategy transformation in
Informatica Mapping
You can define update operation on below two levels:
Update Strategy on Session level:
We can instruct Informatica Service to treat all rows in the same way or use same instruction by configuring Target mapping at session level.
Update Strategy on Mapping level:
You can flag a row (for insert , update, delete or Reject depending upon some condition) by adding "Update strategy Expression" in the properties tab of Update Strategy Transformation in a Mapping. Below Flags can be set in Update strategy Expression.
| Flag |
Numeric Value |
Type Operation |
| DD_INSERT |
0 |
Insert row |
| DD_UPDATE |
1 |
Update row |
| DD_DELETE |
2 |
Delete row |
| DD_REJECT |
3 |
Reject row |
For more details on Update Transformation , Please check
here
A well explained example can be found
here as well.
Expression Transformation in Informatica , is a connected passive transformation (number of input and output rows is the same), which let you modify individual ports of a single row, or add or suppress them. It helps implement the complicated data transforms, applies business logic and performs checks and validations. For example: calculating annual Salary
A well detailed example of Expression Transformation can be found here.
Hope you enjoyed this article, More details can be found at below site
Performance tuning related guideline related expression Transformation can be found here
Must check : Please also check how to create Lookup Transformation
http://www.tecktricks.com/expression-transformation-in-informatica-example-1/
One simple example of this transformation can be creating subject wise row for a student. A well detailed example of Normalization Transformation can be found 
MAPPING LEVEL:It can be done by adding the transaction control transformation in mapping.We can add the required condition in "Transaction control expression"
Example : IIF(DEPT_NO >4 , TC_COMMIT_AFTER,TC_CONTINUE_TRANSACTION)
One simple example of this transformation can be splitting of file depending upon certain field values. A well detailed example of Transaction Control Transformation can be found 