Overview
A transformation is a repository object that generates, modifies, or passes data. The Designer provides a set of transformations that perform specific functions. For example, an Aggregator transformation performs calculations on groups of data.
Transformations in a mapping represent the operations the Integration Service performs on the data. Data passes through transformation ports that you link in a mapping or mapplet.
Transformations can be active or passive. Transformations can be connected to the data flow, or they can be unconnected.
Active Transformations
An active transformation can perform any of the following actions:
♦Change the number of rows that pass through the transformation. For example, the Filter transformation is active because it removes rows that do not meet the filter condition. All multi-group transformations are active because they might change the number of rows that pass through the transformation.
♦Change the transaction boundary. For example, the Transaction Control transformation is active because it defines a commit or roll back transaction based on an expression evaluated for each row.
♦Change the row type. For example, the Update Strategy transformation is active because it flags rows for insert, delete, update, or reject.
The Designer does not allow you to connect multiple active transformations or an active and a passive transformation to the same downstream transformation or transformation input group because the Integration Service may not be able to concatenate the rows passed by active transformations. For example, one branch in a mapping contains an Update Strategy transformation that flags a row for delete. Another branch contains an Update Strategy transformation that flags a row for insert. If you connect these transformations to a single transformation input group, the Integration Service cannot combine the delete and insert operations for the row.
Passive Transformations
A passive transformation does not change the number of rows that pass through the transformation, maintains the transaction boundary, and maintains the row type.
The Designer allows you to connect multiple transformations to the same downstream transformation or transformation input group only if all transformations in the upstream branches are passive. The transformation that originates the branch can be active or passive.
A transformation is a repository object that generates, modifies, or passes data. The Designer provides a set of transformations that perform specific functions. For example, an Aggregator transformation performs calculations on groups of data.
Transformations in a mapping represent the operations the Integration Service performs on the data. Data passes through transformation ports that you link in a mapping or mapplet.
Transformations can be active or passive. Transformations can be connected to the data flow, or they can be unconnected.
Active Transformations
An active transformation can perform any of the following actions:
♦Change the number of rows that pass through the transformation. For example, the Filter transformation is active because it removes rows that do not meet the filter condition. All multi-group transformations are active because they might change the number of rows that pass through the transformation.
♦Change the transaction boundary. For example, the Transaction Control transformation is active because it defines a commit or roll back transaction based on an expression evaluated for each row.
♦Change the row type. For example, the Update Strategy transformation is active because it flags rows for insert, delete, update, or reject.
The Designer does not allow you to connect multiple active transformations or an active and a passive transformation to the same downstream transformation or transformation input group because the Integration Service may not be able to concatenate the rows passed by active transformations. For example, one branch in a mapping contains an Update Strategy transformation that flags a row for delete. Another branch contains an Update Strategy transformation that flags a row for insert. If you connect these transformations to a single transformation input group, the Integration Service cannot combine the delete and insert operations for the row.
Passive Transformations
A passive transformation does not change the number of rows that pass through the transformation, maintains the transaction boundary, and maintains the row type.
The Designer allows you to connect multiple transformations to the same downstream transformation or transformation input group only if all transformations in the upstream branches are passive. The transformation that originates the branch can be active or passive.
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