When using CONNECTION=UNIQUE on a LIBNAME statement, the validity of the
connection string is not checked during the LIBNAME assignment.  When
this occurs, you may see a note in the SAS log indicating that the
LIBNAME was assigned successfully, but when attempting to read or write
to the database via the LIBNAME connection, an error will occur.  An
example would be issuing a LIBNAME statement with the ORACLE engine, but
using an invalid user/password combination.  The error indicating the
invalid user/password combination will not occur when the library is
assigned, but will occur when an attempt is made to read or write to the
library.

This is how CONNECTION=UNIQUE is intended to function.  A connection to
the database is not opened until a table in the database is accessed.

By removing CONNECTION=UNIQUE, the connection is made when the library
is assigned, and any errors will show at that time.

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