[News] Astro-Wise Class Definitions and the consequences for existing databases

[Danny R. Boxhoorn]

Dear Astro-Wiser,

As mentioned during today's telecon a major update of persistent Astro-Wise
classes and their attributes has taken place.
This means that soon we are going to mark these updated classes as STABLE.
In order to move to a new STABLE version the databases at the different
sites have to undergo some serious schema evolution.

There are two possibilities:

- You don't care about your existing database schema and start from scratch.

- You have data you want to keep and choose to evolve the database schema.


Whether you want to evolve the database schema or whether you want to start
from scratch is something you want to discuss locally.
In either case, please contact me after you have decided what you want to do.
For the other two active databases that I'm aware of I suggest that Mike
informs me on behalf of OAC and Jan on behalf of USM.
To influence your decision, I strongly urge you to select the evolution path
even if you want to throw away the data afterwards. Please see this as a
useful exercise in database evolution, because in the future starting from
scratch will no longer be an option. For the same reason We have written down
all the steps we took when evolving the schema at OmegaCEN. It should now be
much easier to perform the required steps than it used to be in the past.

Cheers,

                                                   Danny