What r the mapping paramaters and maping variables?

Maping parameter represents a constant value that U can define before running a session.A mapping parameter retains the same value throughout the entire session.
When u use the maping parameter ,U declare and use the parameter in a maping or maplet.Then define the value of parameter in a parameter file for the session.
Unlike a mapping parameter,a maping variable represents a value that can change throughout the session.The informatica server saves the value of maping variable to the repository at the end of session run and uses that value next time U run the session.


Can U use the maping parameters or variables created in one maping into another maping?

We can use mapping parameters or variables in any transformation of the same maping or mapplet in which U have created maping parameters or variables.


Can u use the maping parameters or variables created in one maping into any other reusable transformation?

Yes.Because reusable tranformation is not contained with any maplet or maping.


How can U improve session performance in aggregator transformation?

use sorted input:

1. use a sorter before the aggregator

2. donot forget to check the option on the aggregator that tell the aggregator that the input is sorted on the same keys as group by.

the key order is also very important.


What is aggregate cache in aggregator transforamtion?

Aggregate cache contains data values while aggregate calculations are being performed. Aggregate cache is made up of index cache and data cache. Index cache contains group values and data cache consists of row values.