calculated identity field in views, again...

I asked this question several weeks ago, but nobody proposed a solution, so
I am repeating the same question again...
I have an MS Access front-end for a database on PostgreSQL.
I could use pass-through queries as record sources for reports and it works
fine...
Unfortunately, MS Access doesn't allow pass-through queries to be records
sources for subforms.
Therefore I tried to base subforms on regular JET queries on linked tables.
It was too slow...
Then I tried to base subforms on DAO recordset code generated from
pass-through QueryDef objects. Although it worked, it was very unstable...

Now it seems to me that POstgreSQL views are the best solution, but Access
considers views as tables (!) and needs column with unique values.
All those views are complicated queries on several tables, so I can't use
any table's column as primary key. I need a calculated column in the view
that Access will consider as primary key column.
In regular tables, I use bigserial field, but how can I create calculated
bigserial column in a view ?

Thanks.