The Table ROOSOURCE is the Header table for SAP BW OLTP Sources.
What kind of information this holds...?
To explain this lets take the example of the Data Source = 0BPARTNER_ATTR (BUsiness Partner).
The following commonly used info is held in this table
OLTPSOURCE = 0BPARTNER_ATTR (name of Data Source)
TYPE = If its an Attribute, text or Hierarchy . IN our case its an attribute.
EXMETHOD = How the data comes , if it comes directly from transparent table or using fixed domain values or function module etc. In our case it comes directly from the standard BP table BUT000.
EXTRACTOR = The source from where the data is got. In our case it comes from the transparent table BUT000.
EXSTRUCT = This is basically the extract structure used. IN our case it is BUS000_BW.
OBJSVERS = Version of the DS.
DELTA = The image of the record.
The table ROOSFIELD is like a Detail table to the Header table ROOSOURCE. The ROOSFIELD table holds the properties of the individual fields of the Data Source.
The important fields to note here are ...
SELECTION = This fields controls if the field of the data source is visible or not and also if it is available for selection.
NOTEXREL = This field decides if the field of the data source will be passed to the extractor or not.
Hope this information helps.
Thanks & Regards,