Generic Delta 2

Question

Dear Expert
I have a z Table consisting fields like company code , change date, etc.
I have created a generic delta using change date as delta field.
A program loads data to this table.
Lets say I loaded all data for company code 1000 and there are other company code data I also need to load but have not done so.
I replicate the datasource to BI 7.
I have read guides on Generic delta and need clarification on its mechanism in more detail.
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1. Do we need to  Initialize Delta for Generic Delta?
2. If  my infopackage used for the init is change date of yesterday, what happens when some days later, I load company code data 2000 into the z table and these data has change dates earlier than the init date?
3. Does init work like this : lets say the data selection in the infopackage used for the init is :
company code = 1000
change date = yesterday.
the 1st delta infopackage will be based on the change date of yesterday and the upper and lower limit?
4. What if I subsequently load other company code data into the z table? How can these be loaded as delta by the existing delta? Or must there be another init? can this be done?
5. Technically, if delta is loaded today, and 2 days later, I insert manually into z table a record having the same change date as the 1st delta change date.  How does the delta mechanism know about this? I seek clarification that this record will not be known by the delta and will not be picked up and loaded by the next delta infopackage because the change date is incremental and will never pick up and old change date and delta is based on change date selection.
Hope you can enlighten me on the above doubts .
Best regards
Pascal

Answer 1

Hi Pascal,
1. Do we need to Initialize Delta for Generic Delta?
Yes, you need to do init to capture the delta records.for this while designing you have to select Delta check box in data source maintenance screen.
2. If my infopackage used for the init is change date of yesterday, what happens when some days later, I load company code data 2000 into the z table and these data has change dates earlier than the init date?
The change date will be populated in Z table based on system, when you change any record today you won't get yesterday date.anyways in your question as change date is less than last delta run date it won't pick that records.
3. Does init work like this : lets say the data selection in the infopackage used for the init is :
company code = 1000
change date = yesterday.
the 1st delta infopackage will be based on the change date of yesterday and the upper and lower limit?
The best practice is run the init with out any selections, unless when you have requirement that you need to create multiple init's on same data source.
no need to give date selections in info package(already your delta is working on change date).If you need data for a particular company code, give company code other even do not give company code as selection.It will pick all the new or changed data from last delta run.
4. What if I subsequently load other company code data into the z table? How can these be loaded as delta by the existing delta? Or must there be another init? can this be done?
Do not give company code as selection in your delta info package.same delta IP will pick the data for all company codes.
5. Technically, if delta is loaded today, and 2 days later, I insert manually into z table a record having the same change date as the 1st delta change date. How does the delta mechanism know about this? I seek clarification that this record will not be known by the delta and will not be picked up and loaded by the next delta infopackage because the change date is incremental and will never pick up and old change date and delta is based on change date selection.
As i already told we cannot give change date manually, when you save a record this will be populated by system in the table.
Delta settings for generic data source will be maintained in table ROOSGENDLM (here we will have last delta run time stamp on this data source).When you run delta next time, it will pick the data which was stored after delta time stamp.
Regards,
Venkatesh.