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Use

The generic BW delta is a delta calculation mechanism for DataSources of object type R3TR RSDS from non-SAP source systems. It can be used for data transfer with DB Connect, UD Connect, using Staging BAPIs, Web Services and for transferring from files.

This method corresponds to the generic delta in the Service API. Using a delta-relevant field whose value rise monotonously over time, the system determines which data to transfer at runtime. An interval for the delta-relevant field is added to the request selections. Using safety intervals at the upper or lower limit of this interval, you can ensure that data records that are created during an extraction process but cannot be extracted (because they could not be saved for example) are looked at during the next extraction. The current lower and upper stamps for the delta-relevant field are stored in a delta pointer table. The next delta uses the last delta stamp to find out which data has to be transferred.

Because of the similiarity to the generic delta in the Service API (SAP source systems including myself and data mart), see the documentation. More information: Delta Transfer Settings.

Procedure

In the DataSource Maintenance transaction (RSDS), you have selected FIL0 Delta with After Images or FIL1 Delta with Delta Images as the delta procedure on the Extraction tab page:

  • With the FIL0 Delta with After Images procedure, each record to be loaded returns the new status for all characteristics and key figures. The values in SAP BW are overwritten. DataSources with this delta type can write data to DataStore objects and master data tables.

  • With the FIL1 Delta with Delta Images procedure, the record to be loaded for cumulative key figures only returns the change to the key figure. The extracted data is added in SAP BW. DataSources with this delta type can write data to DataStore objects and InfoCubes.

The system displays the additional Generic Delta field.

To be able to use the generic BW delta, complete the following steps:

  1. Enter the delta-relevant field type in the Generic Delta field. The following field types are offered: Numeric pointers, date fields and time stamps (short and long)..

    Depending on the delta-relevant field type, the system will show other fields too.

  2. Enter the delta-relevant field in the Data Field field.

  3. The following entries depend on the delta-relevant field type:

    Numeric Pointers:

    In the Lower Interval field, enter the lower saftey interval in the units of the numeric pointer field.

    Note

    For delta determination using a numeric pointer, it is not possible to determine an upper limit the delta, as the system does not know the highest value of the numeric pointer field when the request starts. It is therefore not possible to enter an upper safety interval for the numeric pointer.

    Time Stamp Long (UTC):

    Use Time Stamp Long (UTC) if the data is stored in Coordinated Universal Time (UTC).

    In the Lower Interval or Upper Interval field, enter a lower or upper safety interval in seconds.

    Date and Time Stamp Short:

    Use Time Stamp Short if the data is stored in a local (system) time zone.

    1. Enter the time zone.

    2. In the Lower Interval or Upper Interval field, enter a lower or upper safety interval - in days for date fields and in seconds for time stamp fields.

Result

When the InfoPackage starts, a selection condition is calculated for the delta-relevant field. It is then added to the InfoPackage selections and passed on to the extractor. This extracts the data in full mode, but filters it using the selection conditions.

For data transfer using files, filtering takes place after the data transfer and conversion to BW format and before writing to the PSA. The number of data records in the monitor corresponds to the original (unfiltered) number of records in the file, though only the filtered data is written to the PSA. For the other source systems, the extractor filters the data already and only transfers the filtered data to BW. The number of data records displayed in BW therefore corresponds to the amount of filtered data.