Link Mimer7 Level2 Applications to Mimer SQL 8.2 Category:
Migration
Introduction
If you want to use a Mimer7 level2 application with a Mimer SQL version 8 database server, there are four main approaches to establishing communication:
Description
Re-linking Applications
You can re-link Mimer7 applications for use in a Mimer SQL version 8 environment, accessing a Mimer SQL version 8 database server. We recommend this method for applications running on the same machine as the database server.
On VMS, in this case, the MIMER.OPT file distributed with Mimer SQL version 8 should be used instead of the one distributed with Mimer7. Other Mimer7 libraries that may be used by the application, such as SH (Screen Handler), FM (Forms Manager), etc., should be linked in as before.
On Unix, an application that depends on old modules, such as the runtime components of MIMER/FM, MIMER/SH and MIMER/PG, a compatibility library, called compat.a, is provided for inclusion.
Remapping Shareable Libraries
On VMS, a Mimer7 application can access a Mimer SQL version 8 database server by mapping in the Mimer SQL version 8 sharable image instead of the Mimer7 one. This method is recommended for Mimer version 7 tools, such as PG or QL.
On Unix, MIMER SQL version 8 is distributed as a shared library, this means that an application that was previously statically linked must now employ dynamic load.
Client-Server Access
Mimer7 applications and tools can access a Mimer SQL version 8 database server through the client/server interface without any modification to the application. We recommend this method when the database server on a remote node in the network is of Mimer SQL version 8.
The entry created for a Mimer SQL version 8 database server in the SQLHOSTS file is described in Appendix B of the Mimer SQL System Management Handbook (see links below).
In Mimer SQL version 8, the SERVICE field of the SQLHOSTS file should specify the specific port (TCP/IP) or network object (DECNET) to which the database server listens. If the NODE field is set to the name of the current node and the SERVICE field specifies a local database server, the connection will be established to the local server, using the client/server interface.
For more information, see the Mimer SQL Release Notes delivered with the product.
Environment
Please Note that Level2 is not supported on Linux platforms. If used, you will receive an error message.
Example
Linking Mimer7 application with Mimer SQL version 8 on VMS
The following example is used to link a MIMER/PG application from version 7. LINK application, MIMLIB7:PGML/LIB,PGL/LIB,MIMLIB8:MIMER/OPT
The following example is used to link a MIMER/SH application from version 7. LINK application, coupling file,MIMLIB7:LRU/LIB,SHLIB/LIB, MIMLIB8:MIMER/OPT
The following example is used to link a MIMER/FM application from version 7. LINK application, coupling file, MIMLIB7:LRU/LIB,FMLIB/LIB, MIMLIB8:MIMER/OPT
Linking Mimer7 application with Mimer SQL version 8 on Unix
In the following example the c-compiler “cc” is used to link a MIMER/PG application from version 7.
The shared library libmimer.so and the archive compat.a are taken from a Mimer SQL version 8 distribution on a Unix machine:
On VMS, most user-written applications can be used directly in MimerSQL 8.2 environment by redefining the following logical names, after executing MIMSETUP7: $ DEFINE MIMDB7M MIMDB8 $ DEFINE MIMDB7S MIMDB8 When these names are defined, all applications that were linked with Mimer version 7 will now run in the version 8 environment. You don’t have to re-link the applications if you use this method.
If you want to run Mimer applications such as QL, PG and RG, you can also define a MIMEXE pointing first to MIMEXE8 and then to MIMEXE7.
DEFINE MIMEXE MIMEXE8,MIMEXE7
DEFINE MIMER_DATABASE mydatabase RUN MIMEXE:PGM -- will run PGM version 7 on your version 8 database RUN MIMEXE:BSQL -- will run BSQL version 8 on your version 8 database
On Unix, use the dynamic link /usr/lib/libmimer.so. The example makefiles supplied in Mimer7 and Mimer SQL version 8 provide useful information about loader switches, etc.
Client-Server Access
In the REMOTE part of the SQLHOSTS file, if the NODE field is set to the name of the current node and the SERVICE field specifies a local database server, the connection will be established to the local server, using the client/server interface.
Example of an SQLHOSTS file with a local and a remote definition pointing to the same database
Notes
The Mimer SQL version 8 database server needs a Mimer SQL 8 license located in /etc/mimerkey on Unix, or in SYS$SPECIFIC:[SYSMGR]MIMERKEY.DAT on VMS.
If you re-link Mimer7 applications to use Mimer SQL version 8 shared libraries, you only need a Mimer SQL version 8 license, but it must include the necessary licenses for the Level2 interface.
A single machine will need both licenses if it runs both Mimer7 level2-applications and a Mimer SQL version 8 database server at the same time.
Please note that the Mimer7 application needs a Mimer7 license located in /mimkey7 on Unix. On VMS, the logical name MIMKEY7 points to the file MIMKEY7.DAT located in SYS$SPECIFIC:[SYSMGR]
Benefits
You can easily test your applications in a Mimer SQL 8.2 environment using, for example, the client/server solution.
You will get better performance then if you re-link your applications or re-map the shared libraries.
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