Data Extraction Frequency

[Former Member]

Hello Gurus,

Is it necessary that, there should'nt be any users in R/3 when data is being pulled from R/3. Can I schedule a data pull of sales , purchase, stocks during the day (for eg: during luch time where users are less). Does it depend on the type of extractor. LIS or LO. Please Suggest. Thanks.

[Former Member · Accepted solution]

Hi Roberto,

Thanks for the reply. So it does not matter if the extraction method is LO or LIS.

What I understand is that when delta data is being pulled there is another storage area available to store the online transactions in r/3. and BW switches between the two storage areas, to pull the delta data.

regards.

[Former Member · Accepted solution]

Pradeep,

in LIS you have for one extract structure 'SnnnBIWS’, two tables to manage the delta:

‘SnnnBIW1’ and ‘SnnnBIW2’.

If you start the delta update process from OLTP into BW, the tables SnnnnBIW1 and SnnnBIW2 are taken into account.

For the first delta update, the data from SnnnBIW1 are loaded into BW during the first delta update request.

During first delta update into BW, in the OLTP-system the LIS update process updates the LIS-InfoStructure itself and the table SnnnBIW2, which will then be used for the second delta update request into BW.

Within the beginning of every delta update request there is automatic switch between the tables SnnnBIW1 and SnnnBIW2 to prevent data inconsistency during upload to BW. (Within a delta update in to BW, in the table ‚TMCBIW‘ in the OLTP-system the flag ‚BIW status‘ will automatically switched from 1 (for table SnnnBIW1) to 2 (for table SnnnBIW2).

If you start the second delta update process from OLTP into BW, the table SnnnnBIW2 is now taken into account.

That means, the table ‚SnnnBIW1‘ is used for general LIS updating during the table contents of ‚SnnnBIW2‘ is loaded into the correponding InfoCube in BW.

The table contents of ‚SnnnBIW1‘ will be initialized after the 2. delta update into BW was succesfull (backup).

For delta update into BW there‘s always an automatic switch in the OLTP, to make sure that one table is used for delta upload into BW during the other table is used for the general LIS updating process.

You can view the current active table for the delta updatae wíthin table ‚TMCBIW‘.

For LBWE extractors the mechanism is different but the result is the same!

In addition to V1 and V2 update, synchronous and asynchronous update from the application documents, you have to perform the V3 update (to download your records from delta queue to extraction queue) that you can schedule (this is the main deifference), so it does not update at the time when you process the application documents (for performance reason !), but there are no problem about the consistency of your data !!.

Hope now is clearer (and don't forget to assign some points by clickin'on the yellow star to the contributors that help you !!!)

Bye,

Roberto

[Former Member · Accepted solution]

An excellent analysis, Roberto, as always. Just an addition, in LBWE you can not only use V3 update but there is the possibiliy to use queued delta or direct delta update as described in Note 505700. With PI 2003.1 or later serialized V3 update might be turned off (according to the note).

Best regards

Dirk

[Former Member · Accepted solution]

Sure, Dirk, you are completely right !

I kept the new delta methods out of my previous reply to avoid too long poems (because every method have a different mechanism that have to be described in detail)!

In the next days I will post a weblog on this issue in order to have (I hope) a valid source of info for everyone !

Bye Dirk !

Roberto

[Former Member · Accepted solution]

Thanks Roberto and Dirk. Roberto ur answers r very precise and to the point. I have assigned points to both of u.

rgds,

TR PRADEEP

[Former Member · Accepted solution]

Roberto,

Your detailed information does make it very clear why the SAP creates 2 SnnBIW1, SnnnBIW2 tables, and a structure.

I have another question related to this process.

Once you create a datasource from the custom LIS structures, you can assign a Development class to that datasource.

But the automatically created 2 tables and the structure are local objects, and you cannot reassign them to other object. That is fine because when you export/import the transport, all the other objects are also transported.

But when we enhance the extract structures, it creates a structure ZASnnnBIWS which also HAS TO BE a local object. This creates a problem of how do we transport these changes?

I would appreciate your insight into this.

Thanks

InduBala

[Former Member]

Hi Pradeep,

you can load your delta also during normal production activity (think about someone that have to load his delta hourly !!), but it's recommended to avoid any slowing down of the system by scheduling your jobs when the users logged in are less (so your 'lunch time' option is very good!), because, anyway, when you perform a delta, you need system resources (processes available and so on..)

If you want some more detail, let me know !!!

Bye,

Roberto