D Supporting Changes to XML Schemas

This appendix contains instructions for supporting changes to an XML schema. Extract does not support the capture of changes made to an XML schema.

Topics:

• Supporting RegisterSchema
  RegisterSchema can be handled by registering the schema definition on both source and target databases before any table is created that references the XML schema.
• Supporting DeleteSchema
  Issue DeleteSchema on the source database first.
• Supporting CopyEvolve
  The CopyEvolve procedure evolves, or changes, a schema and can modify tables by adding or removing columns.

Supporting RegisterSchema

RegisterSchema can be handled by registering the schema definition on both source and target databases before any table is created that references the XML schema.

Supporting DeleteSchema

Issue DeleteSchema on the source database first.

Once Replicat is caught up with the changes made to the source database, issue the DeleteSchema call on the target database.

Supporting CopyEvolve

The CopyEvolve procedure evolves, or changes, a schema and can modify tables by adding or removing columns.

The CopyEvolve procedure can also be used to change whether or not XML documents are valid. Handling CopyEvolve requires more coordination. Use the following procedure if you are issuing CopyEvolve on the source database.

1. Quiesce changes to dependent tables on the source database.
2. Execute the CopyEvolve on the primary or source database.
3. Wait for Replicat to finish applying all of the data from those tables to the target database.
4. Stop Replicat.
5. Apply the CopyEvolve on the target database.
6. Restart Replicat.