At 12:51 PM 9/08/2005 +0000, you wrote:

>It seems to me that firebird supports only deferred constraints.

No, it doesn't support deferred constraints.

>Does Firebird support immediate ones?

Yes, only immediate ones.

> If so, how can i change default behaviour to immediate?

The default (and only) behaviour is immediate. A primary key constraint
can be applied to any table that is not currently involved in an
"interesting" transaction.

For foreign key and check constraints, you will get an exception if you try
to apply them when the database is on-line. They must be applied when the
database is off-line, i.e. in "shut down" state. In this state, the
database owner or SYSDBA must log in exclusively. See OpGuide.pdf for the
command

gfix -shut {parameters}

The db owner will not be able to apply constraints to tables it does not
own, nor to apply FK constraints referencing tables to which it does not
have at least the REFERENCES privilege for the column[s] referred to.

./hb