Merge Rows (diff)
Description
Merge Rows (diff) compares two sorted input streams — a reference set and a comparison set — to detect differences between them based on common keys. It flags each output row as identical, changed, new, or deleted, making it useful for identifying what changed between two snapshots of data taken at different points in time. Use this step when you need to synchronize data between systems, especially when the source lacks a last-updated timestamp. Pair it with the Synchronize after merge step to apply the flagged changes as inserts, updates, or deletes on a target table.
Configurations
| Field Name | Description |
|---|---|
| Step name | Specify the name of the step as it appears in the workflow workspace. This name has to be unique in a single workflow. |
| Reference rows origin | Specify the step with reference rows. |
| Compare rows origin | Specify the step with compare rows (new rows). |
| Flag fieldname | Specify the name of the flag field on the output stream. It will contain one of the following values: Identical, Changed, New or Deleted |
| Keys to match | Specify fields containing the keys on which to match; click Get key fields to insert all of the fields originating from the reference rows step |
| Values to compare | Specify fields containing the values to compare; click Get value fields to insert all of the fields from the originating reference and Compare rows steps. Key fields need not be specified here. The Flag fieldname is populated depending on the value in the compare field or the absence of rows for some keys in the compare rows the |