tailieunhanh - Microsoft SQL Server 2008 R2 Unleashed- P231

Microsoft SQL Server 2008 R2 Unleashed- P231:SQL Server 2005 provided a number of significant new features and enhancements over what was available in SQL Server 2000. This is not too surprising considering there was a five-year gap between these major SQL Server 2008 is not as much of a quantum leap forward from SQL Server 2005 | 2264 CHAPTER 54 Managing Linked and Remote Servers useself The setting that determines whether a user or group of users will use their own usernames and passwords to log in to the linked server @useself parameter . There are two possible settings true Local server logins use their own usernames and passwords to log in to the linked server. Consequently the rmtuser and rmtpassword arguments are ignored. For example the local jdoe user with a password of shrek would attempt to log in to the linked server with the jdoe username and shrek password. false Local server logins use the arguments specified in rmtuser and rmtpassword to log in to the linked server. For a linked server that does not require usernames and passwords such as Microsoft Access these arguments can be set to NULL. locallogin The local logins affected by this mapping @locallogin parameter . You can designate either an individual login or all local logins. To specify that all logins be affected you pass a NULL to this argument. rmtuser The username used to connect to the linked server if @useself is set to FALSE @rmtuser parameter . rmtpassword The password used to connect to the linked server if @useself is set to FALSE @rmtpassword parameter . As noted earlier by default after you run sp_addlinkedserver all local logins automatically attempt to use their own usernames and passwords to log in to the new linked server. Essentially SQL Server runs the following statement after sp_addlinkedserver EXECUTE sp_addlinkedsrvlogin @rmtsrvname My_Linked_Server @useself true @locallogin NULL You can delete this default mapping by using sp_droplinkedsrvlogin which is described in the next section. In Windows Authentication mode SQL Server submits the Windows username and password to the linked server if the provider supports Windows authentication and if security account delegation is available on both the client and server. The following example connects all users to the ORACLE_DATABASE linked server using the