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Why do we use mapping parameters and mapping variables?

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Basically, mapping parameters and mapping variables represent values in mappings and mapplets.

Mapping Parameters

  • Mapping parameters represent constant values that are defined before running a session.
  • After creation, parameters appear in Expression Editor.
  • These parameters can be used in source qualifier filter, in user-defined joins, or for overriding.

Mapping Variables

  • As opposed to mapping parameters, mapping variables can change values during sessions.
  • The last value of a mapping variable is saved to the repository at the end of each successful session by the Integration Service. However, it is possible to override saved values with parameter files.
  • Basically, mapping variables are used to perform incremental reads of data sources.

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