anchor.diff:            #   fsync_writethrough
             #   open_sync
   #full_page_writes = <%= node["postgresql"]["full_page_writes"] %>      # recover from partial page writes
  -#wal_buffers = <%= node["postgresql"]["wal_buffers"] %>     # min 32kB, -1 sets based on shared_buffers
  +<%- if node["postgresql"]["wal_buffers"] %>
  +wal_buffers = <%= node["postgresql"]["wal_buffers"] %>     # min 32kB, -1 sets based on shared_buffers
  +<%- end %>
             # (change requires restart)
   #wal_writer_delay = <%= node["postgresql"]["wal_writer_delay"] %>   # 1-10000 milliseconds
   
  
positive.code:           #   fatal
            #   panic (effectively off)
  
  #log_min_duration_statement = <%= node["postgresql"]["log_min_duration_statement"] %>  # -1 is disabled, 0 logs all statements
            # and their durations, > 0 logs only
            # statements running at least this number
            # of milliseconds
  
negative.code:           # in all cases.
  #log_rotation_age = <%= node["postgresql"]["log_rotation_age"] %>      # Automatic rotation of logfiles will
            # happen after that time.  0 disables.
  <%- if node["postgresql"]["log_rotation_size"] %>
  log_rotation_size = <%= node["postgresql"]["log_rotation_size"] %>   # Automatic rotation of logfiles will
  <%- end %>
            # happen after that much log output.
            # 0 disables.
  
  