> Actually, it's not a deadlock - Firebird reports all lock conflicts
> as deadlocks at the top level. It is a lock conflict. And it is
> needed, to protect the referential integrity of the master and its
> related details.
>
> If you don't want referential integrity protection, don't use a

foreign key.

Hello,
I now, but this is not good solution (dont use foreign key) :)
Now, I think to do this:
In separate table I will add record with information that rec id 100
is locked, (id transaction, id connection, id record, user ... )
When user finish lock this record will be deleted.
If something go bad, (record dont be deleted) in triger on connect to
database I will check all record in this table, using id connection
and select list of connection (in FB 2.1 is this feature) and delete
redundance records.
I now, that only SYSDBA or owner database can see this information
about active transaction and connection.

I now, that it is "strange" solution, but I dont have better

Maybe You or some one on group have better :)

Thanks

Piotr