By default, the SQL module language processor, or the SQL
precompiler determines the type of database it attaches to from
the type of database specified in compiling the program. If no
database is used to compile the program, the program is processed
for a database created with the most recent version of Oracle
Rdb.
Specifying the database options in the DECLARE ALIAS statement
overrides the default established in the precompiler or module
processor command lines.
The following table shows the database options for interactive
SQL, SQL module language processor, and SQL precompiler for
OpenVMS.
Table 9 Database Options
SQL
Module and
Precompiler Explanation
RDBVMS Accesses a database created with the most recent
version of Oracle Rdb.
RDB030 Accesses Oracle Rdb Version 3.0 databases.
RDB031 Accesses Oracle Rdb Version 3.1 databases.
RDB040 Accesses Oracle Rdb Version 4.0 databases.
RDB041 Accesses Oracle Rdb Version 4.1 databases.
RDB042 Accesses Oracle Rdb Version 4.2 databases.
RDB050 Accesses Oracle Rdb Version 5.0 databases.
RDB051 Accesses Oracle Rdb Version 5.1 databases.
In most cases, it is not necessary to specify a database option.
For example, when you attach to an Oracle Rdb Version 7.0
database, SQL provides the V7.0 features.
However, you need to specify a database option when the database
you attach to during compilation or precompilation has different
features than the database against which the program is to run.
You must specify a database option that provides the "lowest
common denominator" of features for all the databases that the
program intends to use at run time.
If no database is used during compilation of the program, the
program is processed for a database created with the most recent
version of Oracle Rdb. Therefore, if the resulting program is
intended to run against a database other than the most recent
version of Oracle Rdb, you must specify that version of the
database option during compilation.
You can use any of the qualifiers listed in Database Options to
override the default database option.