Concurrent SELECT and UPDATE in multiprocessing python
As I dug deeper into the matter at hand trying various approaches I found out that there is no solution to this problem with PostgreSQL versions &lt;= 9.4.

PostgreSQL 9.5 (current development version) has a new feature called SKIP LOCKED which does skip rows that have been locked by a query using SELECT * ... FOR UPDATE

For more information on the new feature have a look at http://www.depesz.com/2014/10/10/waiting-for-9-5-implement-skip-locked-for-row-level-locks/