$ENV{LD_LIBRARY_PATH} = "$ENV{LD_LIBRARY_PATH}://usr/lib/oracle/11.1/client64/lib/";
$ENV{ORACLE_HOME} = "/usr/lib/oracle/11.1";

my $dbh = DBI->connect("dbi:Oracle:$dbName\@$dbHost:$dbPort", $dbUser, $dbPass) or
          die("DB Error '$DBI::errstr");

DBI connect('dbName@host:1521','user',...) failed: ORA-12154: TNS:could not resolve the connect identifier specified (DBD ERROR: OCIServerAttach) at ./cgi-bin/assigned.pl line 28
DB Error 'ORA-12154: TNS:could not resolve the connect identifier specified (DBD ERROR: OCIServerAttach) at ./cgi-bin/assigned.pl line 28.

ORA-12154: TNS:could not resolve the connect identifier specified
 *Cause:  A connection to a database or other service was requested using
 a connect identifier, and the connect identifier specified could not
 be resolved into a connect descriptor using one of the naming methods
 configured. For example, if the type of connect identifier used was a
 net service name then the net service name could not be found in a
 naming method repository, or the repository could not be
 located or reached.
 *Action:
   - If you are using local naming (TNSNAMES.ORA file):
      - Make sure that "TNSNAMES" is listed as one of the values of the
        NAMES.DIRECTORY_PATH parameter in the Oracle Net profile
        (SQLNET.ORA)
      - Verify that a TNSNAMES.ORA file exists and is in the proper
        directory and is accessible.
      - Check that the net service name used as the connect identifier
        exists in the TNSNAMES.ORA file.
      - Make sure there are no syntax errors anywhere in the TNSNAMES.ORA
        file.  Look for unmatched parentheses or stray characters. Errors
        in a TNSNAMES.ORA file may make it unusable.
   - If you are using directory naming:
      - Verify that "LDAP" is listed as one of the values of the
        NAMES.DIRETORY_PATH parameter in the Oracle Net profile
        (SQLNET.ORA).
      - Verify that the LDAP directory server is up and that it is
        accessible.
      - Verify that the net service name or database name used as the
        connect identifier is configured in the directory.
      - Verify that the default context being used is correct by
        specifying a fully qualified net service name or a full LDAP DN
        as the connect identifier
   - If you are using easy connect naming:
      - Verify that "EZCONNECT" is listed as one of the values of the
        NAMES.DIRETORY_PATH parameter in the Oracle Net profile
        (SQLNET.ORA).
      - Make sure the host, port and service name specified
        are correct.
      - Try enclosing the connect identifier in quote marks.

   See the Oracle Net Services Administrators Guide or the Oracle
   operating system specific guide for more information on naming.