HP 3000 Manuals HP 3000 Manuals
Maintaining ALLBASE/SQL Applications
After ALLBASE/SQL C programs are in production use, changes in
procedures, personnel, or databases may necessitate various changes in
the application itself. Maintaining an ALLBASE/SQL program includes such
activities as these:
* Tuning performance.
* Managing the source code.
* Updating a program in production use.
* Changing runtime authorizations as program users change.
* Obsoleting application programs.
For these activities, you need OWNER authority for the module or DBA
authority.
Tuning Performance
When an application enters production, you can estimate the best
allocation of system resources, but only after it has run for a while can
you fine-tune the performance. Refer to the ALLBASE/SQL Performance
Guidelines for additional information about "Controlling Performance."
The best performance also depends on good transaction management. Refer
to the ALLBASE/SQL Reference Manual for additional discussion of
transaction management.
Managing Source Code
You should carefully maintain the source code for each application
program in case it should be necessary to re-preprocess and re-compile at
a later time. In addition to C source, it is recommended that you keep
copies of the ISQL command files used to create your DBEnvironments.
This information is extremely useful when modifying existing code.
Use SQLGEN to create schema files for storage once you have configured
the DBEnvironment on the production side. Refer to the ALLBASE/SQL
Database Administration Guide for information about using SQLGEN.
Updating Application Programs
Minor modifications to programs in the production environment can be made
while the program is not currently in use. Major program modifications,
because they are more time-consuming, are usually made on a development
machine in a development DBEnvironment.
In either case, the OWNER of the program's module (or a DBA) preprocesses
the revised program and replaces the old module with a new one. Existing
RUN authorities can be either preserved or revoked. Dropping old modules
and preserving or revoking RUN authorities can be done by using the DROP
MODULE command in ISQL or can be specified when you invoke the
preprocessor.
The PRESERVE option of the DROP MODULE command retains any existing RUN
authorities for the module when it is deleted from the system catalog:
isql=> DROP MODULE myprog PRESERVE;
To delete a module and any existing RUN authorities for that module,
simply omit the PRESERVE option.
You can also drop a module and revoke any existing run authorities for it
at preprocessing time:
: RUN PSQLC.PUB.SYS; INFO="SOMEDBE (MODULE (MODULENAME) DROP REVOKE)"
The DROP option tells the preprocessor to drop any existing module named
MODULENAME; if you omit the DROP option, a new module is created only if
a module named MODULENAME does not exist. This invocation line drops any
existing module named MODULENAME, and revokes any related RUN
authorities. To revoke the RUN authorities by specifying the REVOKE
option in the INFO string, you must also drop the module by specifying
the DROP option.
The DROP MODULE command is also useful for revised programs whose modules
must be installed in a DBEnvironment different from that on which
preprocessing occurred. Before using the INSTALL command to store the
new module, drop the existing module using the DROP MODULE command,
preserving or dropping related RUN authorization as required.
Changing Program-Related Authorization
Once a program is in production use, you may need to grant and revoke RUN
and CONNECT authority as program users change. Revoking CONNECT
authority requires DBA authorization:
isql=> REVOKE CONNECT FROM OLDUSER@ACCOUNT;
Revoking RUN authority requires either module OWNER or DBA authority:
isql=> REVOKE RUN ON PGMR1@ACCOUNT.SOMEPGM FROM OLDUSER@ACCOUNT;
Dropping Obsolete Modules
When an application program becomes obsolete, you use the DROP MODULE
command to both remove the module from any DBEnvironment where it is
stored and revoke any related RUN authorities:
isql=> DROP MODULE myprog;
Related RUN authorities are automatically revoked when you do not use the
PRESERVE option of this command.