2.1.2.4 [XMLSCHEMA1/2] 4.2.2 Including modified component definitions

V0039:

The specification states the following:

 In order to provide some support for evolution and versioning, it is possible to incorporate components corresponding to a schema document with modifications. The modifications have a pervasive impact, that is, only the redefined components are used, even when referenced from other incorporated components, whether redefined themselves or not....
  
 A <schema> information item may contain any number of <redefine> elements. Their schemaLocation attributes, consisting of a URI reference, identify other ·schema documents·, that is <schema> information items.
  
 The ·XML Schema· corresponding to <schema> contains not only the components corresponding to its definition and declaration [children], but also all the components of all the ·XML Schemas· corresponding to any <redefine>d schema documents....

Microsoft SQL Server 2008 R2 and Microsoft SQL Server 2012 vary as follows:

Transact-SQL does not support this element. XML schemas that include the xsd:redefine element are rejected by the server.

To update a schema or its components, the user can take the following steps instead:

Create a new XML Schema collection with the modified schema components.

Retype all xml data types (XML DT) that use the XML Schema collection and that are to be redefined to use the new XML Schema collection. To do this, use the ALTER COLUMN option of the ALTER TABLE command for retyping columns, or change the XML Schema collection constraints on variables or parameters.

See [ISO/IEC9075-1:2011] for the definitions of "column" and "constraint".

Drop the old version of the XML Schema collection.

This variation pertains to XML Schemas [XMLSCHEMA1/2] [XMLSCHEMA2/2] functionality in SQL Server.