EXEC sp_configure 'show advanced options', 1

 GO

 RECONFIGURE

 GO

 EXEC sp_configure 'Ad Hoc Distributed Queries', 1

 GO

 RECONFIGURE

 GO

SELECT

    MAX(OldestCall)

FROM

(

    SELECT

        FeildAA As FeildAAFROM  OPENDATASOURCE('SQLOLEDB','Data Source=1270.0.1;User ID=sa;Password=sa').DBNameA.dbo.TableNameA AS A

    INNER JOIN OPENDATASOURCE('SQLOLEDB','Data Source=127.0.0.1;User ID=sa;Password=sa').[DBNameB].[dbo].[CMS_TableNameB] AS B ON A.ID= B.ID

) AS AA