Mimer SQL Developers - Howto - Use Mimer V7 applications with Mimer SQL V8 on Unix

Use Mimer V7 applications with Mimer SQL V8 on Unix
Category: Migration

Introduction

Mimer version 7 (V7) included a number of libraries and utilities that were not SQL-based. For example:

QL Old Query Language
PG Program Generator
FM Forms Manager
SH Screen Handler
RG Report Generator
QF Query by Forms
PI Old API for Database Access

All development on these modules stopped about ten years ago, and the Mimer SQL version 8 distribution does not include these modules.

However, the Mimer SQL version 8 database (V8) server is still compatible with all the earlier tools. This document shows how you can use V7 modules such as QL, PG, SH and FM together with V8 on Unix.

Description

If you want to use a Mimer7 Level2 application with a Mimer SQL version 8 database server, you can:

Connect to the database using the client/server interface, i.e. from a Mimer7 client node to a Mimer SQL version 8 server node.

Re-map the shareable libraries distributed with Mimer SQL version 8.

Re-link the MIMER7 application to include the shareable images distributed with MIMER8 and the compatibility library.

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 Mimer SQL version 8.

It is possible to use the client/server interface locally, i.e. having a remote database definition pointing to a local database server. This is the recommended access method when using Mimer SQL version 7 tools, such as QL and PG, towards a Mimer SQL version 8 database.

Re-mapping Shareable Libraries
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.

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 Unix, a compatibility library, called compat.a, is provided for inclusion for applications that depend on old modules, such as the runtime components of MIMER/FM, MIMER/SH and MIMER/PG.

Example

Client-Server Access
To achieve this, the SQLHOST file must be updated in a specific way using a 6^th parameter in the remote definition, as shown in the following example (current node is “startrek”, i.e. where the Mimer SQL version 8 database “m8server” runs):


DEFAULT:
--
-- Database
-- ---------------------------------------------------------------------------
   SINGLE
-- ===========================================================================
LOCAL:
--
-- Database           Path
-- ------------------ --------------------------------------------------------
   SINGLE             .
   m8server           /database/m8server:/mnt1/m8server:/mnt2/m8server
-- ===========================================================================
REMOTE:
--
-- Database           Node               Protocol Interface Service
-- ------------------ ------------------ -------- --------- ------------------
   example_database   server_nodename    ''       ''        1360
   m8access           startrek           ''       ''        1360      m8server

To access the “m8server” database, the Mimer SQL version 7 application must connect to the database “m8access”.

In this case the “startrek” node must have both a Mimer SQL version 7 license (for the application) and a Mimer SQL version 8 license (for the database server). The Mimer SQL version 8 license must include a specific license in order to be able to accept client/server connections.

If you want to run a version 7 application on a version 8 database in client/server environment you have to define an entry for both MIMER8 and MIMER7 in /etc/inetd.conf and to define different port i /etc/services.

/etc/inetd.conf:


mimer8 stream tcp nowait root /usr/bin/mimtcp mimtcp –l
mimer7 stream tcp nowait root /opt/products/mimer7/bin/netsrvm netsrvm mimer tcp inetd

/etc/services:


mimer8   1360/tcp
mimer7   1371/tcp

Re-mapping Shareable Libraries
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.

Linking a 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:

cc  -o pgappl pgappl.o \
/home/mimer7/lib/pgfml.a \
/home/mimer7/lib/pgl.a \
/home/mimer7/lib/lru.a \
/home/mimer7/lib/fmlib.a \
/usr/lib/libmimer.so \
/usr/lib/compat.a -lm –lcurses

Notes

The Mimer SQL version 8 database server needs a Mimer SQL 8 license located in /etc/mimerkey on Unix.

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.

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 than if you re-link your applications or re-map the shared libraries.

Links

Mimer SQL System Management Handbook, HTML-navigation.

Mimer SQL System Management Handbook, PDF-file, 735KB.

Last updated: 2002-08-21