SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Managing Database Applications
HP NonStop SQL/MX Installation and Management Guide—523723-004
11- 3
Migrating SQL/MX Applications From Release 2.0 to
Release 2.1
For information about how to recustomize and SQL compile SQLJ applications, see the
SQL/MX Programming Manual for Java.
Migrating SQL/MX Applications From Release 2.0 to Release 2.1
You can migrate and run Release 2.0 applications in a Release 2.1 environment
without having to recompile them.
Moving Programs From Development to
Production
Theoretically at least, there are two approaches to move an application from a
development system to the production environment:
•
Moving a program with compiled modules
•
Moving a program without compiled modules
However, there are very few circumstances under which you can compile a program’s
modules on a development system and then move the program and modules to a
production system without recompiling the modules there. See Reasons Not to Move a
Program With Compiled Modules.
HP recommends that you always move a program from a development system to a
production system and then compile module definitions on the production system. See
Moving a Program Without Compiled Modules on page 11-4.
Reasons Not to Move a Program With Compiled Modules
You are advised not to move a program and its compiled modules to a production
system because:
•
This approach is likely to cause automatic recompilation of query execution plans.
•
Automatic recompilation imposes a high cost on program performance.
When you move a program and its compiled modules to the production system, the
query execution plans undergo a similarity check and possible automatic recompilation
when you execute the program on the production system. The SQL/MX executor
initiates a similarity check because the compile-time definition timestamp of the query
execution plan, which is based on tables on the development system, differs from the
run-time definition timestamp of the tables on the production system.
Note. If you recompile a Release 1.8 application in the Release 2.x environment, that
application cannot query SQL/MP tables on Release 1.8 nodes. The recompiled application
can query SQL/MP tables on Release 2.x nodes only. You must upgrade remote Release 1.8
nodes to Release 2.1 or Release 2.0 for SQL recompiled applications to access SQL/MP
tables on those nodes.