I modified the posted SQL to use Left Joins as suggested and indeed my Link to Oracle now shows up. It was missing before and I had noticed that the join to logins could be an issue.

SELECT

a.NAME

,a.product

,a.provider

,a.data_source

,a.catalog

,f.name

,b.uses_self_credential

,b.remote_name

FROM

sys.servers AS a

left JOIN

sys.linked_logins AS b

ON a.server_id = b.server_id

Left JOIN

sys.server_principals AS f

ON b.local_principal_id = f.principal_id

I notice that this query also returns the instance which is the first row in sys.servers. I added a "where a.name <> a.data_source" which filters the instance out but I am not sure this is safe for all cases. Is another or different condition necessary to filter out the instance?

-- Mark D Powell --