Dimitry Sibiryakov wrote:

> That's sad. And it became even more sad because system tables don't
> have PKs. It means that I can't prevent user from dropping table that
> my application depends on. Can't create FK to system table. Not sure
> about triggers... If I create triggers for system table will they
> survive during backup/restore?

Not sure if they will survive (didn't check) but even if they do, they won't
load. You just have to define a trigger in a sys table, close all
connections to it (the server detaches it) and reconnect. The user trigger
on the sys table won't execute because it's not loaded.

> IBReplicator is an example of application that suffer from this
> "feature". It'll crash if someone drop table for which there are
> pending operation in log.

Well, that's not that bad if you consider that we have users that take
advantage of high level tools to change system tables directly and later
come whining that their db doesn't work correctly.
:-)

C.