I need little help.

Our company is implementing Oracle BI 10.x. We don't have much
experience in Siebel Analytics/OBI.

We have few fact tables e.g. W_XXXX_F, which we need/wish to extend.
We are not sure about which methodology we should implement. When we
talked with few SA experts they mentioned we need to extend based on
ROW_WID. Well, this column doesn't exists anymore in many fact tables,
so currently we are thinking of creating ROW_WID on this F table
manually and then create WC_XXXX_FX and take these two tables in
physical layer of RPD.

Additially, we need to create few Informatica mappings, again SA
experts pointed out to use Image tables. Our data source is Oracle
Applications, I don't have much idea about Image tables, but clearly
there is not S_ETL_I_IMGAGe or so tables in Oracle Apps

Please guide us as how to proceed on these two issues.