> Because the datastore has no schema the interfaces need to define the schema > themselves - as Java objects and some annotations. So if you are already > defining the schema at the data model level it makes sense to define changes > there too. > > Do you mean use the low-level api instead to alter the data? In that case > you still need to configure the interface to read/write the new format - so > may as well reuse it, no?
This is the point were we differ. To me it makes all sense to prepare a low-level API for schema migration, but I would not bind it to the current mappings. I mean, the possibilities here are just too many, and the up-to-date persistence mappings are not relevant to do the migration. They seem to be more of a hassle than helpful for that purpose. I may be wrong, so I am just asking. I was comparing the examples given here with what would be the equivalent of porting to GAE the typical schema upgrade script, and didn't see much benefit in it. > I do remember something in HIbernate that could generate "update table" > scripts from changed config files. But I guess with all back ends they had > to support it was a much tougher job. AFAIK they have something to create the DDL, but then you should use your own database tools to create the upgrade script. -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
