>>> Quite. And does this also include "logical" corruption,
>>> that is, when the database gets into some inconsistant
>>> state at a high level? It seems that there are a few
>>> known issues of this sort. Are they to be considered as
>>> simply bugs?

> Well, they're certainly not features. There is some
> disagreement in my family about adding constraints to a
> populated database. I think the system should check that
> the constraint is consistent with the state of the database
> before the constraint is added. My beloved thinks that's
> unreasonable - slow etc.

I accept that it may be slow but for my purposes the most
significant reason for system like Firebird is data integrity.
If it lets me break integrity it is not doing its job.

I suspect that this aspect begins to have impact on another
thread going on here at the moment - as to whether DDL should
occur in the same transaction as DML etc. In order for DDL
to be validated against existing data it must "see" all
relevant existing data - which implies involvement with DML
transactions.

--
Geoff Worboys
Telesis Computing