NonStop SQL/MP Reference Manual

NonStop SQL/MP Reference Manual—142115
A-46
Considerations—ALTER VIEW
Changing a column heading in a view does not change the corresponding heading in
any view previously created on that view. A view inherits headings from underlying
tables and views when you create it, but the headings then exist independently.
SIMILARITY CHECK { ENABLE | DISABLE }
authorizes or prohibits similarity checks on a protection view. (You cannot specify
this clause for a shorthand view.)
Authorizing similarity checks (SIMILARITY CHECK ENABLE) on a view whose
version is older than 310 increases the version of the view (and the version of
objects that depend on the view) to 310. Such a view cannot be registered in an
older version catalog or accessed by older versions of NonStop SQL/MP.
Prohibiting similarity checks (SIMILARITY CHECK DISABLE) on a view that has
version 310 decreases the version of the view (and the version of objects that depend
on the view).
Considerations—ALTER VIEW
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Authorization requirements
To rename a view or alter security attributes for a view, you must be a generalized
owner of the view. You must also have authority to read the view.
You must have authority to read and write to the catalogs that describe the view and
any associated objects. If you rename a view, all dependent programs are
invalidated.
If a view to be renamed is a protection view, then the underlying table and indexes
must be accessible and you must have read and write authority.
Only one DDL statement can operate on a given SQL object (or partition of an SQL
object) at a time. An error occurs if you attempt to execute an ALTER VIEW
statement while another process is executing a DDL operation on the same object.
The specific error depends on the DDL operation involved and the phase of the
operation at which the conflict occurs. (See DDL (Data Definition Language)
Statements on page D-19 for more information.)
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Version management considerations
Changing an attribute of a view can change the version of the view (and the version
of objects that depend on the view).
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General dependencies for ALTER VIEW