SQL/MX 2.x Database and Application Migration Guide (G06.23+, H06.04+, J06.03+)

Converting SQL/MP Applications to SQL/MX
Applications
HP NonStop SQL/MX Database and Application Migration Guide—540435-005
10-60
Using Row-Value Constructors
execution plans on a per table basis, NonStop SQL/MX allows you to use the
CONTROL QUERY SHAPE statement to force the entire query execution plan.
For more information, see the
SQL/MX Query Guide.
Using Row-Value Constructors
In NonStop SQL/MP, you typically use row-value constructors (or multivalue
predicates) in repositioning logic to help the optimizer create a plan that positions
correctly instead of scanning the table.
In NonStop SQL/MX, a table scan might still occur when you use row-value
constructors. However, you might still get an efficient plan for this type of query if the
SQL/MX optimizer chooses the MultiDimensional Access Method (MDAM).
For more information about how MDAM processes predicates, see the
SQL/MX Query
Guide. For more information about predicates, see the SQL/MX Reference Manual.
Moving the Application From Development to
Production
After all testing of a new SQL/MX application is complete, move the application from
the development system to a production system. If the application is an embedded
SQL/MX application, compile the module definitions, which are either embedded
module definitions or module definition files, on the production system.
When planning for migration, determine an optimal time for cutover from the SQL/MP
application to the new SQL/MX application. The optimal time for cutover is when there
is minimal risk for disruption to applications on the production system, typically when
business traffic and system demands are low. The optimal cutover time for your new
SQL/MX application depends on your unique database environment and business
needs.
Ensuring Optimal Performance in Production
For optimal performance of the SQL/MX application in the production environment,
make sure that:
•
The table structure and distribution of the data are similar between the
development and production systems.
•
The default settings are the same on the development and production systems.
•
The table statistics are up-to-date on the production system.