How can i find the datasource?

BW de aktifleştirilecek datasource’un hangi veri alanlarını(field) aktifleştireceğinin görülmesi;

•    Hi Gurus,
We have a scenario of extracting Y Reports in R/3 to BW.
i have documented set of tables which behind the each Y reports.
Now how can i indentified the standard datsources from the set of tables.
•    how to find the corresponding database table for the specific data source fields?
•    You can find the data source fieds in ROOSFIELD table for a given datasource.
•    The table to find datasource in R/3 is ROOSOURCE.

Once u get name of the datasource you could run the extractor checker to see if data exists using RSA3.