You might know and appreciate the capabilities to generically define delta when building a DataSource in SAP source systems. But you had a lot of work, if you want to load delta data from any other source system type, like DBConnect, UDConnect or File. You could declare the data is delta, ok, but this had no real effect, it was just declarative. The task to select the correct data from the source was still yours.
Now with BW 7.30 this has changed. Because now there is – the generic BW delta!
As expected, you start by defining a BW DataSource.
Nothing new, up to now. But if you choose that this DataSource is delta enabled, you will find a new dropdown:
These are the same options that you already know from the SAP source system DataSource definition:
Ok, let’s see what happens if we select “Date”.
The fields “Delta Field” and the two interval fields you know already from the generic delta in the SAP source system. And they have the same meaning. So hopefully I can skip the lengthy explanation of the Security Margin Interval Logic and come to the extra field which popped up: The Time Zone. Well ok, not very thrilling, but probably useful: Since the data in your source might not be saved at the same time zone like the BW which loads it (or your local time), you can explicitly specify the time zone of your data.
“Time stamp – short” offers quite the same input fields, except that the intervals are given in seconds rather than days. “Time stamp Long (UTC)” is by definition lacking the “Time zone” field. Let’s watch “Numeric Pointer”:
Oops – no Upper Interval! I guess now I do need to spend some words on these intervals: The value given in “upper Interval” is subtracted from the upper limit used for selecting the delta field. Let’s say current upper value of the delta field is 100. The upper interval is 5. So we would need to select the data up to value 95. But hold on – how should the system know the current value of the numeric field without extracting it? So we would extract the data up to the current upper value anyhow – and hence there is no use in specifying an upper interval.
The lower limit in turn is automatically parsed from the loaded data – and thus known before the next request starts. And hence we can subtract the safety margin before starting selection.
Our example DataSource has a UTC time stamp field, so let’s select it:
Activate the DataSource and create an InfoPackage:
CHANGED is no selectable field in the InfoPackage. Why not? Well, the delta selections are calculated automatically. You do not need to select explicitly on them. Now let’s not forget to set the update mode to Init in order to take advantage of the generic delta:
Wait a minute! There is a new flag: “Switch InfoPack. in PC to Delta (F1)”. Guess I need to press F1 to understand what this field is about.
Sounds useful, doesn’t it? No more maintenance of two different InfoPackages and process chains for delta upload! You can use the same InfoPackage to load Init and Delta like in the DTP.
In our small test we do not need a process chain, so let’s go on without this flag and load it. Then let’s switch the InfoPackage to Delta manually and load again.
Indeed, there are selections for our field CHANGED.
Don’t miss any of the other Information on BW 7.30 which you can find SAP Business Warehouse 7.3