SAP BW ......Operational Data Source

Q. What is ODS?Ans. Operational Data Source; used for detailed storage of data (like document level); you can overwrite existing data in ODS (in cube you cannot); you can also drill down from cube to ODS; used for data consolidation and cleansing; the data is stored in a flat table ( unlike the extended star schema of the cube); so using SE11/SE16, you can query the ODS data directly.

Q.What are the table structures associated with ODS?Ans.Active data, new data and the change log table.
Q.What is the use of change log?Ans.Change log is used for delta updates to the target; it stores all changes per request and updates the target.

Q. How do you delete change log?Ans.AWB → right click on ODS →Manage →environment→ delete change log

Q.What are the advantages of using ODS in a infoset for reporting?Ans.
a.Access via OLAP engine
b.infosets can join flat BW objects like master data attributes etc.,
Q.what are the new features of ODS after version 3.x?Ans.
a. you can load and activate ODS in parallel
b. No M table
c.secondary indexes are created in ODS objects itself
d.selectiv deletion

Q.what is transactional ODS object?Ans. This has only the active table; this is filled using APIs; you report on this using Infoset only; usually used for applications like SEM

Q.What is the unique data records flag?Ans.If you enable then when ODS gets duplicate record (identical to one in Activetable), it rejects with an error. Use this feature to load a cube filtering any duplicates( cubes will simply add up duplicates)