A-SYB-DEFAULT-CONNECTION is the name of the server to which the runtime will connect. The default value of this variable is the value of the environment variable DSQUERY (this is a Sybase variable, and so should be set in your environment. See the Sybase documentation for ISQL.) If neither variable is set, the default server is named SYBASE, just as for ISQL. To reference tables in another server, open the file servername.database.owner.table.
Example
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, then you should set:
A-SYB-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
See also
The Sybase documentation on ISQL.