I' m new in Pentaho. I'm trying to get Pentaho to do somewhat equivalent to COBOL. In COBOL, there is a working storage where variables are declared so that current values can be checked against previous values. The working storage in COBOL also stores switches and flags. I wonder how it can be done in Pentaho? I'd like to set a flag or a switch on every input record that is read in Pentaho. I also wonder how I can store records in Pentaho so that I can do computation such as adding current amount to the previous amounts. A working model would be helpful.

Thanks,