Question:
Hello Everyone,
Could someone tell me the significance of 'before images'/ 'after images'.
Also, how do we work with them.
Thanks in advance.
Answer:
Hello Everyone,
Could someone tell me the significance of 'before images'/ 'after images'.
Also, how do we work with them.
Thanks in advance.
BW Delta Process: Update Mode
This indicator describes how a record in the delta process is updated. The various delta processes support different combinations of the six possible characteristic values. If a DataSource implements a delta process that uses several characteristic values, the indicator must be a part of the extract structure and be entered in the DataSource as a cancellation field (ROOSOURCE-INVFIELD).
The six characteristic values are as follows:
' ': The record delivers an after image.
The status is transferred after something is changed or added. You can update the record into an IncoCube only if the corresponding before image exists in the request.
'X': The record delivers a before image.
The status is transferred before data is changed or deleted.
All record attributes that can be aggregated have to be transferred with a reverse +/- sign. The reversal of the sign is carried out either by the extractor (default) or the Service API. In this case, the indicator 'Field is inverted in the cancellation field' must be set for the relevant extraction structure field in the DataSource.
These records are ignored if the update is a non-additive update of an ODS object.
The before image is complementary to the after image.
'A': The record delivers an additive image.
For attributes that can be aggregated, only the change is transferred. For attributes that cannot be aggregated, the status after a record has been changed or created is transferred. This record can replace an after image and a before image if there are no non-aggregation attributes or if these cannot be changed. You can update the record into an InfoCube without restriction, but this requires an additive update into an ODS Object.
'D': The record has to be deleted.
Only the key is transferred. This record (and its DataSource) can only be updated into an ODS Object.
'R': The record delivers a reverse image.
The content of this record is the same as the content of a before image. The only difference is with an ODS object update: Existing records with the same key are deleted.
'N': The record delivers a new image.
The content of this record is the same as for an after image without a before image. When a record is created, a new image is transferred instead of an after image.
The new image is complementary to the reverse image.
The table RODELTAM determines which characteristic values a delta process uses (columns UPDM_NIM, UPDM_BIM UPDM_AIM, PDM_ADD UPDM_DEL and UPDM_RIM). The table ensures that only useful combinations of the above values are used within a delta process.
When extracting in the 'delta' update mode in the extracted records for the indicator, a DataSource that uses a delta process can deliver only those characteristic values that are specified in the delta process.
Please refer also to the OSS Note 399739 'Questions and answers on InfoObject 0RECORDMODE'.
You use Full Load when you :
- just do a one shot of an extraction
- or when you are sure that you will get only new data (can be day after day, and no data for the previous were modified or deleted)
This can be used for FI purposes. Fiscal period after fiscal period (by example), you can do a Full Load of this fiscal period, because the FI documents may not be modified.
You use Last Status, when :
- you may load once a document (Sales Order quantity 120 pce)
- then with another load, the same document comes again, it is modified and you do not get the modification but the last situation (sames Sales Order with now quantity 150 pce).
If you push that to a cube, your final quantity may be 270 pce, and you do not want that. With Last Status, you can update the ODS, then get the delta done inside BW.
You use Additive Data when
- with the same situation above, your new extraction does not contain the new situation, but its evolution. So, the new extract would contain + 30 pce. That can be pushed to a cube directly.
So, everything depends on the delta capabilities of your extractor. Maybe you do not need a delta (like for FI documents), maybe you can not get it (Last Status), maybe you have it (Additive data).
Depending on the situation, then you always do a Full Update (FI documents again), or ypu need to Initialize a Delta procedure to :
- occur a delta inside BW with the ODS (Last Status)
- accept a delta done in the source system (Addivite delta)
So, you would get an image or initial situation of the first load from your source system, then get/build the delta.
Answer:
Hope this should help.........
http://help.sap.com/saphelp_bw33/helpdata/en/84/81eb588fc211d4b2c90050da4c74dc/frameset.htm