The delta process is a feature of the extractor and specifies how data is to be transferred. As a DataSource attribute, it specifies how the DataSource data is passed on to the data target. This can be used to find out certain things, for example which data targets a DataSource is best suited for, and how the update and serialization will be carried out.
The delta process type affects how an InfoProvider is supplied with updated data. When an ODS object is supplied with updated data, the object needs to be serialized so that the data can also be overwritten. Depending on the delta process, the system decides whether to serialize by request or by data package.
There are various delta processes for SAP source systems:
Forming deltas with after, before and reverse images that are updated directly in the delta queue. An after image shows the status after the change, a before image the status before the change with a negative sign and the reverse image also shows the negative sign next to the record while flagging it for deletion. This serializes the data packages. The delta process stipulates whether adding or overwriting is permitted. In this case, adding and overwriting are both permitted. This process supports updates in a DataStore object as well as in an InfoCube. (Technical name of the delta process in the system: ABR)
The extractor delivers additive deltas that are serialized by request. This serialization is required because the extractor in a request delivers each key once, and changes in the non-key fields are otherwise not copied over correctly. It only supports addition of fields. It supports updates in a DataStore object as well as in an InfoCube. This delta process is used by LIS DataSources. (Technical name of the delta process in the system: ADD)
Forming deltas with after image, which are updated directly in the delta queue. This serializes data package by package, as the same key can be copied more than once in a request. It does not support direct updating of data in an InfoCube. Data in an InfoCube can only be updated if a DataStore object is in operation. For numeric key figures for example, this process only supports overwriting and not adding, as this would produce incorrect results. It is used in FI-AP/AR to transfer line items, while a variation of the process where the extractor can also send records with the deletion flag is used in BBP. (Technical name of the delta process in the system: AIM/AIMD)
The 0RECORDMODE field stipulates whether the records are added to or overwritten. It defines how a record is updated in the delta process. Leaving it blank returns an after image, 'X' a before image, 'D' deletes the record and 'R' returns a reverse image.