1)We need to read data from a different database (adw) in to FDI to create data modelling on top of it. So took the following approach but it gives error saying query against given schema is not allowed.

>Using Admin schema which has a db link created to pull data and load them in view. Public synonym is created and then access granted to oax_user and oax$oac.

>Tried taking the synonym in data flow/Semantic model but unable to retrieve the attributes with error query against given schema is not allowed.

>What will be the best practice here? Is admin not the correct schema to be used? Do we have the possibility to create db link from oax_user?

2)What will be the best practice to create mat views which involves a select query joining standard tables of FDI with tables from diff db(using db link as explained above).Which schema is best to use and how to refresh or schedule them?

3)Any objects created inside admin schema. What will be the impacted of it during FDI upgrades or patching?

Looking forward to get answers for all the above queries which is needs to be implemented as a part of our new project.