This
statement is used to either enable or disable the decomposition support
for a specific XML schema. Annotated XML schemas can be used to decompose
XML documents into relational tables, if decomposition has been enabled
for those XML schemas.
Invocation
The ALTER XSROBJECT statement
can be embedded in an application program or issued through the use
of dynamic SQL statements. It is an executable statement that can
be dynamically prepared only if the DYNAMICRULES run behavior is in
effect for the package (SQLSTATE 42509).
Authorization
One of the following authorities
is required:
- DBADM
- ALTERIN on the SQL schema
- Ownership of the XSR object to be altered
Syntax
>>-ALTER--XSROBJECT--xsrobject-name----------------------------->
>--+-ENABLE DECOMPOSITION--+-----------------------------------><
'-DISABLE DECOMPOSITION-'
Description
- xsrobject-name
- Identifies the XSR object to be altered. The xsrobject-name,
including the implicit or explicit schema qualifier, must uniquely
identify an existing XSR object at the current server. If no XSR object
with this identifier exists, an error is returned (SQLSTATE 42704).
- ENABLE DECOMPOSITION or DISABLE DECOMPOSITION
- Enables or disables the use of the XSR object for decomposition.
The identified XSR object must be an XML schema (SQLSTATE 42809).
In order to enable decomposition, the XML schema needs to be annotated
with decomposition rules (SQLSTATE 225DE) and the objects referenced
by the decomposition rules must exist at the current server (SQLSTATE
42704).
Notes
- When decomposition for an XSR object is disabled, all related
catalog entries are removed.
- Decomposition support for an XSR object will be disabled if any
objects the XSR object depends on (such as tables) are dropped or
altered to become incompatible with the XSR object.
- In a partitioned database environment, you can
issue this statement by connecting to any partition.
DB2 10.5 for Linux, UNIX, and Windows