Setting Input Order and Tagging

Using the Inputs tab in the Merge and Append node dialog boxes, you can specify the order of input data sources and make any changes to the tag name for each source.

Tags and order of input datasets. Select to merge or append only complete records.

• Tag. Lists current tag names for each input data source. Tag names, or tags, are a way of uniquely identifying the data links for the merge or append operation. For example, imagine water from various pipes that is combined at one point and flows through a single pipe. Data in IBM® SPSS® Modeler flows similarly, and the merging point is often a complex interaction between the various data sources. Tags provide a way of managing the inputs ("pipes") to a Merge or Append node so that if the node is saved or disconnected, the links remain and are easily identifiable.

When you connect additional data sources to a Merge or Append node, default tags are automatically created using numbers to represent the order in which you connected the nodes. This order is unrelated to the order of fields in the input or output datasets. You can change the default tag by entering a new name in the Tag column.

• Source Node. Displays the source node whose data is being combined.
• Connected Node. Displays the node name for the node that is connected to the Merge or Append node. Frequently, complex data mining requires several merge operations that may include the same source node. The connected node name provides a way of differentiating these.
• Fields. Lists the number of fields in each data source.

View current tags. Select to view tags that are actively being used by the Merge or Append node. In other words, current tags identify links to the node that have data flowing through. Using the pipe metaphor, current tags are analogous to pipes with existing water flow.

View unused tag settings. Select to view tags, or links, that were previously used to connect to the Merge or Append node but are not currently connected with a data source. This is analogous to empty pipes still intact within a plumbing system. You can choose to connect these "pipes" to a new source or remove them. To remove unused tags from the node, click Clear. This clears all unused tags at once.