SQL/MX 3.2.1 Reference Manual (H06.26+, J06.15+)

SQL/MX Statements
HP NonStop SQL/MX Release 3.2.1 Reference Manual—691117-005
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Considerations for CREATE VIEW
SIMILARITY CHECK, you can enable Similarity Check for a view. Similarly, by
specifying DISABLE SIMILARITY CHECK, you can disable Similarity Check for a view.
Restrictions for Similarity Check
•
Nested views and views with a VALUES clause are not supported.
•
View Similarity Check is not supported for SQL/MP views.
Reserved View Names
View names prefixed by the name of a UMD table are reserved. You cannot create
views with such names. For example, you cannot create a view named
HISTOGRAMS_MYVIEW.
Effect of Adding a Column on View Definitions
The addition of a column to a table has no effect on any existing view definitions or
conditions included in constraint definitions. Any implicit column references specified
by SELECT * in view or constraint definitions are replaced by explicit column
references when the definition clauses are originally evaluated.
Authorization and Availability Requirements
To create a view, you must own the schema and have SELECT privileges for the
objects underlying the view.
When you create a view on a single table, the owner of the view is automatically given
all privileges WITH GRANT OPTION on the view. However, when you create a view
that spans multiple tables, the owner of the view is given only SELECT privileges
WITH GRANT OPTION. If you try to grant privileges to another user on the view other
than SELECT you will receive a warning that you lack the grant option on that privilege.
Updatable and Non-Updatable Views
Single table views can be updatable. Multi-table views cannot be updatable.
Note. The CQD, DDL_VIEW_SIMILARITY_CHECK controls the Similarity Checks for views at
the system level. The ENABLE or DISABLE SIMILARITY CHECK clauses in the CREATE
VIEW and ALTER VIEW statements take precedence over the CQD setting. The default setting
for this CQD is ENABLE.
The following lists the CQD settings and behavior:
°
ENABLE/SYSTEM - If the view definition permits, Similarity Check is enabled,
else Similarity Check is disabled
.
°
ON - If the view definition permits, Similarity Check is enabled, otherwise the view
is not created or altered, and an error is returned.
°
DISABLE/OFF - Similarity Check is disabled.