Postgresql 9.4.1 stuck all queries when making multi updates
There was a bug with commit_delay in PostgreSQL 9.4.X. It was just fixed, and the fix will appear in version 9.4.5. See the thread on the PostgreSQL mailing list: http://www.postgresql.org/message-id/CACKh8C-tDjQUceMQeG3BUSHS5AA35SjvCD6HgRm-Vj7x5rXmeQ@mail.gmail.com