which is the best

hii all,
Now I have 3 database A,B,C is working in Interbase v 5.6,
but Interbas v 5.6 is no longger can hold what the client wants,
I will conver it in Postgresql, I need your advice which is the
bertter result:

(1):
 unika (schema)
    |
    |------ A
    |------------ B
    |------------------- C

(2) create database A, create database B, create database C

thank you all