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This Blog is Regarding how to recover recently missed delta using Reconstruction method.

Missed delta load from One DSO to another DSO or from One DSO to Cube.

Business Scenario

This article explains how to load recently missed delta using Reconstruction method (3.x flows) in BI system.

This method can be used if the delta load is taking place:


  1. From one DSO to other DSO.
  2. From DSO to cube.
  3. From Cube to Cube.

There are two ways to load missed delta one is the repair full load and other is load manually missed delta using reconstruction method.

Delta Concept

SAP BW supports two types of updates in which data can be loaded into SAP BW. The full update always extracts all data for the fields of a transfer structure. The second type of update is the delta update, which only extracts data that has changed since the last load process or that is new. Delta updates are especially suited to large data masses so that data does not have to be loaded into SAP-BW multiple times. Deltas can also be transferred from the source systems with extractors so that complete transfers can be avoided.

Reconstruction Condition

Reconstruction can be performed on cube in BI7.0 only and it can be performed on cube if it is 3.x flows Info Package.To reconstruct the requests the data for the corresponding requests must be available in PSA.This function can be used to fill a DataStore object with requests that have already been loaded into the BI system or another DataStore object.Reconstruction can be used is only for DataStore objects that obtained their data from InfoPackages.Reconstructing the DataStore object gives data from the change log, so the delta can be loaded into the Reconstructed DataStore.Requests can be used to reconstruct the current InfoCube or construct another InfoCube.If the requests contained in the InfoCube were already rolled up in aggregates or in BI accelerator indexes, then these requests cannot be used for reconstruction. Only the last (uppermost) requests can be used for reconstruction.

Advantages

  1. Take lesser time to load recently missed delta compared to repair full.
  2. If there is no date selections(like Cal-day) in Info Package then this method will be efficient compared to repair full load.

Step By Step Solution

Here we are taking the scenario for Example: Source is DataStore Object (DSO) and Target is InfoCube(Cube).If the delta load has failed from past 2-3 days from DSO to Cube, we can load the entire missed delta from DSO to Cube request by request using reconstruction method. To perform this operation follow the below steps.

  1. Delete the error requests from the Cube by forcibly changing the status to red (do it even the request is red) at the monitor screen and also in manage data of the Cube.
  2. Delete the data mart from the source DSO.

To delete the data mart perform the following steps.

  1.      Right Click on DSO.
  2.      Then click on manage option of the DSO.
  3.      Go to the request tab and click on Data Mart Status of Requests.

Image 0.png

   d.       It will prompt for new screen (in the below screenshot)

   e.       To confirm that the correct data mart is being deleted, Click on the Display Request monitor.

   f.        It will redirect to monitoring screen there you can verify the Data Target System (in this case it is Cube)


Image1.png

    g.    Click on Reset Delta Management (Delete option).

It will prompt to “Are you sure to reset the delta management”.

Click on yes.


Image 2.png

      h.     By clicking on Yes tab Data mart will be deleted.

3. Now delete the all failed delta request from source DSO (Requests What are not loaded to target Cube) after deleting the data mart.

4. Now Load the data from DSO to Cube.

5. Check if the delta has pulled any record (Missed delta) or not.

6. If it has pulled 0 records to from DSO to Cube, then there may be chance that Cube’s delta has been corrupted.

To initialize the delta perform the following steps.


Steps to Initialize the Delta.

1. Go to the update tab of Info Package and select “Initialize Delta Process” and then select “Initialize Without Data Transfer.

Image 3.png

2. Now Go to the Schedule Tab on Info Package and click on Start.

    Now it will prompt for “Deltas already loaded for requests …(old init Request in)….init. Selection; no 2 init”.


Image 4.png

3. Go to Scheduler tab (Top left of the screen) of Info Package and select the “Initialization Options for Source System”.

Image 5.png

4. Now select the previously initialized delta request, without making red the monitor status of previously initialize request and click on delete.

Image 6.png

5. Now It will prompt for “Deleting initializations affects Data Store Object” click on ok.

Image 7.png

6. Check if there is any selections in the previously initialize delta.

7. It will again prompt for

  “There are active init selections in the source system for this data source

   Therefore, only ALL init selections canbe deleted once

   Do you want to delete all init selections (all channels)”

   Click on Yes.


Image 8.png

         The previously initialize delta will be deleted.

8. Now go to the Schedule option of the Info Package and click on Start.

9. After successful initialization of delta load the missed delta from source to target.

Steps To perform Reconstruction of the requests.

1. Now go to reconstruction tab of the source DSO and select the first deleted (request which loaded first to the DSO) request and click on reconstruct/Insert option.

 

   If the requests were deleted by making monitor status red then it will prompt for

    “Request ….. is not marked as correct

     This request cannot be used for reconstruction!

     Ignore the request?”

Image 9.png

2.     Now go to monitor screen by clicking on “Display Request Content” of the deleted request and make the monitor status green.

Image 10.png

3.     And then again click on Reconstruct/Insert option.

      Message will be displayed at left bottom of screen “ Reconstruction scheduled for DataStore/Cube …(Name) “.


Image 11.png

4. Now after reconstruction load the data from DSO to Cube.


5. Now again go to the reconstruction tab of DSO and reconstruct one more request and load the same to the target Cube one by one(Reconstruct one request      and load the same request from DSO to cube ,again reconstruct one request and load the same request from DSO to Cube).


6. Perform above steps till the last request gets loaded successfully.

      Similarly the reconstruction method can also be used in Full Load.

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