Change detection (diff/delta)

Change detection is a feature of dexi.io that can be used to determine when specific values of robot execution results change. Change detection can also be seen as diffing or delta functionality.

Output values from the robot that you choose are compared from the current execution with the previous execution; in effect, providing a sliding window of changes.

Enable change detection

Contact us if you would like this feature enabled on your account.

1. Search for change detection in Apps.
2. Select Contact Dexi.

Configure change detection

Once the app is enabled, the feature is enabled for a configuration of a robot by checking the Track changes? checkbox:

The Key fields define the fields that are used to determine the uniqueness of a row (i.e., when the values of the key fields match across the previous and the current execution). The values from the Value fields are then compared:

• If values are new, the row is marked as Created.
• If values are unchanged, the row is marked as Existed.
• If values have changed, the row is marked as Changed.
• If values were deleted, the row is marked as Deleted.

A field cannot be selected as both a key and value field and currently, only non-file, non-object, and non-array/list fields (i.e., simple fields), are supported for both key and value fields.

Results with change detection

The change status is added to the results as a separate field, Change — called @change when results are exported or when using change detection from triggers.

Example showing only Changed rows:

If any rows were deleted, they are shown on the Deleted results tab.

The Old value prefix controls the name of the old fields, i.e., the fields of the rows of the previous execution. In the example below, the prefix previous- has been entered:

If left blank, the prefix old- is used.

Change detection with triggers

The old value fields and the @change field are available from triggers and can be mapped just like the normal fields from the result rows:

See also:

• Datasets with deduplication and record linkage