NonStop SQL/MP Reference Manual

Table Of Contents
NonStop SQL/MP Reference Manual142115
D-59
Considerations—DOWNGRADE SYSTEM
CATALOG
You can express version as either an integer (2, 300, 310, 315, 320, 325, or 330)
or a character string (A011, A300, A310, A315, A320, A325, or A330), but the
version you specify must be older than the current version of the system catalog.
You cannot downgrade a catalog to version 1, but version 2 catalogs are compatible
with version 1 software.
Considerations—DOWNGRADE SYSTEM CATALOG
Authorization and access requirements
Only the local super ID can downgrade a system catalog.
DOWNGRADE SYSTEM CATALOG requires exclusive access to the system
catalog. Other processes cannot access the system catalog during the downgrade.
The downgrade fails if another process has one of the catalog tables in the system
catalog open when you execute DOWNGRADE SYSTEM CATALOG.
If you downgrade a system catalog to version 2, file labels must be available during
the downgrade for any tables or objects registered in the catalog that have a nonzero
value for the OBJECTVERSION column of the TABLES or INDEXES catalog
table. (For backward compatibility, DOWNGRADE CATALOG changes such file
labels to specify object version 0.)
Restrictions on contents and version of system catalog
You cannot downgrade a system catalog that contains protection views, objects with
a version newer than version, or programs with a PCV newer than version.
(Drop any such objects or programs before you execute DOWNGRADE SYSTEM
CATALOG.) In addition, a system catalog cannot itself have a version newer than
the version of the NonStop SQL/MP software executing the DOWNGRADE
SYSTEM CATALOG command.
You can downgrade a system catalog that has higher-version user catalogs registered
in it. For example, you can downgrade a version 310 system catalog to version 2,
even if it has version 310 user catalogs registered in it.
Program invalidation
DOWNGRADE SYSTEM CATALOG invalidates any program that refers to a
catalog table in the downgraded system catalog, but does not invalidate a program
merely because the program is registered in a downgraded system catalog or
accesses an object (such as a user table) described in a downgraded system catalog.
DOWNGRADE SYSTEM CATALOG does not invalidate a program registered in
the downgraded system catalog that has a PFV newer than version because such
a program can execute regardless of the catalog downgrade unless the NonStop
SQL/MP software that executes the program is replaced with an older version.
However, if the purpose of the DOWNGRADE SYSTEM CATALOG is to prepare
for installation of an older version of NonStop SQL/MP software, you will need to
re-SQL-compile programs with a newer PFV after the older software is in place. (A
runtime error occurs if you attempt to execute a program with a PFV newer than the
installed NonStop SQL/MP software.)