Schema evolution (more than TSD2 -> TSD3 migration)

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1

hello!

i have the impression that it might be an occasional task to change the schema definition of a collection. For example when new [mandatory] elements are added to document types or types of simple elements change.

when a browsed the documentation i found quite a lot of (ineresting) material on TSD2 → TSD3 migration. this seems to be well possible and is supported in a nice manner.

my question is: does it work in the same way for simple TSD3 → TSD3 schema evolution ? I tried to change the type of a simple element from xs:IDREF to xs:String (using the schema editor). when i tried to define the schema inside the database this change was rejected because my old schema (and the data were already/still there).

so, is evolution possible? where do i find documentation ?

thanks in advance,
Raimund

2

… is possible with Tamino. The basic restrictions since Tamino 3.1 are:
- all (say: many) schema modifications are possible, which grant that all existing documents will validate vs. the new schema. E.g.
- adding an optional element/attribute
- extending cardinality ranges, e.g. lower minOccurs or raise maxOccurs

With Tamino 4.1 there will be an additional option which allows more changes to the schema: then all instances will be explicitly validated vs. the new schema.

3

hello and thanks for your reply.

i found that snipped of documentation that says that evolution is okay as long as it does not become more strict.

question is: how is it done practically? do i just define the new schema with the tsd3 schema editor?

thanks a lot,
Raimund

4

Yes, you change the schema and define it or validate it before define.
Thus if you define an existing schema again its an update.

5

hi!

thanks a lot. i got it now.

wouldn’t it be nice if the migrator application (tsd2 → tsd3) would also support schema evolution ? this define-migrate-test-finish approach is really good. it should be available for evolution…

Raimund