The good thing with linked servers is, you can write queries to fetch the data from a remote server (via linked) in your sql procedures and more.
We happened to test the connectivity of a oracle server due to an upgrade. When a new Linked server connection is created using the UI and ran a sql to fetch the data from a oracle table, Sqlserver connection throw ed an error message
Msg 7319, Level 16, State 1, Line 1
The OLE DB provider “OraOLEDB.Oracle” for linked server “ORACLEUAT” returned a “NON-CLUSTERED and NOT INTEGRATED” index “O_AD_EM” with the incorrect bookmark ordinal 0.
The solution to this problem is to force the oracle indexes to be ignored by changing the option “Index as access path” on the OraOLEDB.Oracle provider.