Operations ‣ Diff

The Diff operation can be used to compare two data sets. One data set is the comparison source (reference / e.g. an older data set), the other data set is the main source (the current/new data). The following data records are made available on four outputs:

• Unchanged: Data for which no change has been detected.
• Changed: Data that is present in both data sets but has been changed.
• Added: Data that was not yet present in the reference data set.
• Deleted: Data that was present in the reference data set and is now missing

Please note: The two data sets used must contain the same columns/attributes.

For better understanding an example:

The reference table (older data set): Download CSV

product_id	name	color	price
1	Chair	Red	50
2	Table	Blue	120
3	Lamp	White	30
4	Shelf	Black	80

The source table (current/new data): Download CSV

product_id	name	color	price
1	Chair	Red	50
2	Table	Blue	150
3	Lamp	Green	35
5	Sofa	Gray	200

The key attribute is product_id. After executing the Diff with “Detect deleted values” enabled, the four outputs contain the following:

Unchanged — records where all values are identical in both data sets:

product_id	name	color	price
1	Chair	Red	50

Changed — records present in both data sets but with at least one changed value:

product_id	name	color	price
2	Table	Blue	150
3	Lamp	Green	35

Product 2 changed in price (120 → 150), product 3 changed in color (White → Green) and price (30 → 35).

Added — records in the source that do not exist in the reference:

product_id	name	color	price
5	Sofa	Gray	200

Deleted — records in the reference that are no longer present in the source:

product_id	name	color	price
4	Shelf	Black	80

The configuration:

1. assign a name for the diff
2. the key attribute/key column must be present in both data sets and the values must be unique
3. the deleted values are not determined by default and no data appears on the output. The output is activated with this switch.