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- 9
Moving Applications to a Remote Node
•
If you compile an application from a Release 2.0 node that queries a Release 2.1
node, the query plan version will be the same as the earliest node version in the
distributed database (1200).
•
When you compile an embedded SQL/MX application, a query execution plan will
have a plan version equal to the earliest MXV of all its referenced nodes, or it will
have a plan version equal to the MXV of the node where you compile the
application if that MXV is earlier than the referenced node’s MXV.
•
If you fall back a remote node from Release 2.1 to Release 2.0 after compiling
embedded SQL/MX applications, any applications compiled on a Release 2.1 node
that refer to database objects on the Release 2.0 node will fail to execute and will
return an error at run time stating that the application cannot access database
objects on the Release 2.0 system. This error occurs because version 1400 query
execution plans cannot run on a Release 2.0 system. To run the application, you
must explicitly recompile the application to generate version 1200 plans for queries
that refer to the Release 2.1 node that fell back to a Release 2.0 node.
For more information, see Versioning Issues on page 1-12.
Moving Applications to a Remote Node
To move an application to a remote node (where the metadata for the application’s
objects does not reside), move the application files and recompile the module
definitions on the remote node. Do not attempt to copy the module file for that
application to the remote node. Note that this approach risks generating a query plan
on the remote node that differs from the query plan on the original node.
See Moving Programs From Development to Production on page 11-3 for detailed
instructions about how to move application files and modules to a remote node.
Running Applications on a Remote Node
In a distributed database environment:
•
You can always run a local Guardian or OSS application from the local node by
running the local program file.
•
You can run a local Guardian or OSS application on a remote node by copying the
application to the remote node and running the remote program file there.
•
To run a remote Guardian or OSS application from the local node, you must copy
the application from the remote node to the local node, then recompile the module
definitions for that application from the local node.
Using REGISTER CATALOG to Access Objects on Remote
Nodes
Statements in an embedded SQL program can refer to SQL/MX objects on a remote
node without changes to the database object names in the source code. However, the