A_MSSQL_DEFAULT_CONNECTION specifies the name of the server to which the run time system connects. If A_MSSQL_DEFAULT_CONNECTION is not set, a server name of localhost is used. To reference tables on a server other than the one specified by this variable, open the file using the following syntax:servername.database.owner.table.
Suppose you have two servers, one named TOM and one named HARRY. If most of the tables you want to access are on the server HARRY, you should set:
A_MSSQL_DEFAULT_CONNECTION HARRY
For those occasions when you want to access the TOM server, you could open the file this way:
TOM.stores.johndoe.purch1