SQL/MP to SQL/MX Database and Application Migration Guide

HP NonStop SQL/MP to NonStop SQL/MX Database and Application Migration Guide—666211-001
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Falling Back to NonStop SQL/MP
This chapter describes falling back from NonStop SQL/MX to NonStop SQL/MP. Plan
for a potential fallback to NonStop SQL/MP before you install NonStop SQL/MX and
start developing SQL/MX applications and database objects. That way, if necessary,
you can fall back from NonStop SQL/MX more easily. For more information, see
Planning for Fallback
on page 3-3.
If you encounter a serious problem with NonStop SQL/MX and need to fall back to a
SQL/MP environment, read this chapter before attempting the fallback procedure.
Steps for Falling Back to NonStop SQL/MP
Because NonStop SQL/MP and NonStop SQL/MX can coexist on a NonStop system
and NonStop SQL/MP is available on each RVU of the NonStop system, falling back to
NonStop SQL/MP from SQL/MX does not require that you reinstall an earlier RVU.
You cannot use SQL/MX applications developed before falling back to SQL/MP
database objects if you drop referenced SQL/MX objects or if you uninstall NonStop
SQL/MX.
To fall back to NonStop SQL/MP, complete the following steps:
1. Stop using the SQL/MX applications.
2. Resume using the SQL/MP applications and database objects.
3. To reclaim the space used by the SQL/MX database objects, identify and drop all
the SQL/MX database objects, including both user tables and system metadata
tables.
a. To determine a complete list of SQL/MX schemas on the system, query the
system metadata. For example, the following command returns all the
schemas, including system schemas, that are visible on the node named
FIGARO:
>> set schema nonstop_sqlmx_figaro.system_schema;
>> select substring(schema_name,1,30) as schema_name,
substring(cat_name,1,20) as cat_name, node_name
from schemata s, catsys c, cat_references cr
where s.cat_uid=c.cat_uid
and c.cat_uid=cr.cat_uid
and cr.replication_rule='A';
SCHEMA_NAME CAT_NAME NODE_NAME
Note. While using new features, if you encounter a problem that is specific to NonStop
SQL/MX, consider discontinuing the use of those features instead of falling back.