Correct RHD. If not fully qualified, system tables (including VSTs) return data from the database with the DICTDB alias. By default it will be the first connected database.
You can show which DB it is with "display ldbname("dictdb")". If you want data from multiple DBs you can do this by iterating over your connected DBs and changing the DICTDB alias. Note that you can't set and reference the alias within the same procedure. See
this thread for an example.
As Stefan noted in that thread you can do it in a single procedure if you're comfortable with dynamic queries.