Opening a database in exclusive mode

I have a question when connecting to Interbase 5, SQL Server 7 and Oracle 8
using the BDE.

TDatabase.Exclusive documention does not guarantee that SQL based servers
support this property. Does anybody know if it works for Interbase, SQL
Server 7 and Oracle 8?

I have the same question when using ADO. Does the property Acces{*word*237}ission
works for Jet 4, SQLServer 7 and Oracle 8?

Thanks for any help!