I have an abstract class Event with 2 subclasses AlarmEvent and ManageEvent.
AlarmEvent has a boolean acknowledged
ManageEvent has a boolean confirmed

I would like to query
for Event
where AlarmEvent.acknowledged (true|false)
(or|and)
ManageEvent.confirmed (true|false)

But using a simple case my queries don't provide results that match the database.
So, obviously I am missing something in how to set up the query.

Here is one sample query:
select event from Event event, AlarmEvent alarm, ManageEvent manage
where alarm.acknowledged = false or manage.confirmed = false

However, with a DB having 2 entries:
Alarm acknowledged true and
Manage confirmed false
the result set included both events

Any hints on how to make this kind of query using HSQ?

It is hard to guess what mapping you are using. Why don't you just paste it here?

I'm not a HQL guru, but for me your query does not care about AlarmEvent and ManagedEvent at all, because it just says "select event from Event". The rest does not matter bacause there is no restriction on event's properties

Try something like

select event from Event event,
AlarmEvent alarm,
ManageEvent manage
where (event = alarm and alarm.acknowledged = false) or
(event = manage and manage.confirmed = false)

That does it - thanks