Explain the difference between mapping parameter and mapping variable in Informatica?

Question

I am using a stored procedure as a source in my Informatica mapping, and I have defined the SQL query in the source qualifier as

exec dbo.GET_ATTRIBUTES($$fromDate, $$toDate)

where $$fromDate and $$toDate are mapping parameters I have defined in a parameter file. I have tried a number of different ways of going about this and none seem to work, as the SQL query fails to validate.

So, my question boils down to this, is there a way to call a stored procedure while passing in two mapping parameters?

Thanks in advance

Answer 1

When values change during the session's execution it's called a mapping variable. Upon completion the Informatica server stores the end value of a variable and is reused when session restarts. Moreover those values that do not change during the sessions execution are called mapping parameters. Mapping procedure explains mapping parameters and their usage.
Values are allocated to these parameters before starting the session.