Paul,
What is the current schema layout for your db instances? I don't think
it's possible to share across db instances like this:
dbname1.myschema.sometable
dbname2.myschema.sometable
But you can share resources of the following type:
dbname.myschema1.sometable
dbname.myschema2.sometable
dbname.myschema2.sometable2
dbname.myschema2.sometable3
I think that it's a mis-statement to call each separate schema a DB, but
the group of:
dbname.myschema2.(collection of objects) is effectively a separate DB,
in that, the tables are what constitute a functional db.
so you can treat
dbname.myschema1.(...)
and
dbname.myschema2.(...)
as separate databases that share common resources, because they belong
to the same db instances, namely "dbname"
