Difference between Mapping Parameters and Variables

A mapping parameter represents a constant value that we can define before running a session. A mapping parameter retains the same value throughout the entire session. If we want to change the value of a mapping parameter between session runs we need to Update the parameter file.

A mapping variable represents a value that can change during the session. The Integration Service saves the value of a mapping variable to the repository at the end of each successful session run and uses that value the next time when we run the session. Variable functions like SetMaxVariable, SetMinVariable, SetVariable, SetCountVariable are used in the mapping to change the value of the variable. At the beginning of a session, the Integration Service evaluates references to a variable to determine the start value. At the end of a successful session, the Integration Service saves the final value of the variable to the repository. The next time we run the session, the Integration Service evaluates references to the variable to the saved value. To override the saved value, define the start value of the variable in the parameter file.