Thank you Lele for previous answer!
Here I re-ask about some minor themes:

1) For "historical reasons" our database does not use foreign keys, so we
have to do everything "by hand" with triggers. Can the "no-use" of FK
decrease performance?

2) We take advantage of the "position" feature of the interbase-triggers.
There are differences, in performance, between a big trigger doing A+B+C
actions and 3 small triggers (in sequence) doing the same A+B+C actions?

3) Are there some tuning I can do to give to "ibserver.exe", on win-os,
more in-memory resources? (I think it is very "kind" with ram)

Thank you in advance