Three types of DSO in BI 7.0

Question

Hi,
I went through the sap help documents related to the three types of DSO.
1. Standard
2. Direct Update
3. Write Optimized
Still not clearly understood in which case we use what kind of DSO's.  Could any one explain me that in your own words.
I am new to BI, your explanation is appreciated.
What is this ADP process that is used using the Direct Update DSO.........Any docuements or links or info on it?
Thanks,

Answer 1

DataStore Objects for Direct Update
DataStore objects for direct update ensure that the data is available quickly. The data from this kind of DataStore object is accessed transactionally. The data is written to the DataStore object (possibly by several users at the same time) and reread as soon as possible.
It is not a replacement for the standard DataStore object. It is an additional function that can be used in special application contexts.
<b>APD -</b>
In the BI system, you can use a DataStore object for direct update as a data target for an analysis process
In the BI system data is collected from the heterogeneous databases in the various systems that the enterprise is using and is consolidated, managed, and staged for evaluation purposes. There is often further, valuable potential in this data.
This is completely new information that is displayed in the form of meaningful correlations between data but that is too well hidden or complex to be discovered by simple observation or intuition.
The Analysis Process Designer (APD) allows you to find and identify these hidden or complex relationships between data in a simple way. Various data transformations are provided for this purpose, such as statistical and mathematical calculations, data cleansing and structuring processes.
The results of the analysis are saved in BI InfoProviders or in CRM systems. They are available for all decision and application processes and thus can be decisive (strategically, tactically, and operatively).
Examples of analysis processes include the calculation of ABC classes, determination of frequency distribution or of scoring information.
http://help.sap.com/saphelp_nw04s/helpdata/en/49/7e960481916448b20134d471d36a6b/content.htm
<b>Standard DataStore Object</b> The standard DataStore object is filled with data during the extraction and load process in the BI system.
It has 3 tables - New , Active , Change log table
<b>Write-Optimized DataStore Objects</b>
Data that is loaded into write-optimized DataStore objects is available immediately for further processing.
You use write-optimized DataStore objects in the following scenarios:
&#9679;     You use a write-optimized DataStore object as a temporary storage area for large sets of data if you are executing complex transformations for this data before it is written to the DataStore object. Subsequently, the data can be updated to further (smaller) InfoProviders. You only have to create the complex transformations once for all data.
&#9679;     You use write-optimized DataStore objects as the EDW layer for saving data. Business rules are only applied when the data is updated to additional InfoProviders.
The system does not generate SIDs for write-optimized DataStore objects and you do not need to activate them. This means that you can save and further process data quickly. Reporting is possible on the basis of these DataStore objects. However, we recommend that you use them as a consolidation layer, and update the data to additional InfoProviders, standard DataStore objects, or InfoCubes.
http://help.sap.com/saphelp_nw04s/helpdata/en/f9/45503c242b4a67e10000000a114084/content.htm
Hope it Helps
Chetan
@CP..