SELECT round(100.0*checkpoints_req/checkpoints,1)                                                  "Forced checkpoint ratio (%)",
       round(min_since_reset/checkpoints,2)                                                        "Minutes between checkpoints",
       round(checkpoint_write_time::numeric/(checkpoints*1000),2)                                  "Average write time per checkpoint (s)",
       round(checkpoint_sync_time::numeric/(checkpoints*1000),2)                                   "Average sync time per checkpoint (s)",
       round(total_buffers/128.0,1)                                                                "Total MB written",
       round(buffers_checkpoint/(128.0*checkpoints),2)                                             "MB per checkpoint",
       round(buffers_checkpoint/(128.0*min_since_reset*60),2)                                      "Checkpoint MBps",
       round(buffers_clean/(128.0*min_since_reset*60),2)                                           "`bgwriter` MBps",
       round(buffers_backend/(128.0*min_since_reset*60),2)                                         "Backend MBps",
       round(total_buffers/(128.0*min_since_reset*60),4)                                           "Total MBps",
       round(100.0*buffers_checkpoint/total_buffers,1)                                             "Clean by checkpoints (%)",
       round(100.0*buffers_clean/total_buffers,1)                                                  "Clean by `bgwriter` (%)",
       round(100.0*buffers_backend/total_buffers,1)                                                "Clean by backends (%)",
       round(100.0*maxwritten_clean/(min_since_reset*60000/bgwriter_delay),2)                      "`bgwriter` halt-only length (buffers)",
       coalesce(round(100.0*maxwritten_clean/(nullif(buffers_clean,0)/bgwriter_lru_maxpages),2),0) "`bgwriter` halt ratio (%)",
       round(1.0*buffers_alloc/total_buffers,3)                                                    "New buffer allocation ratio",
       min_since_reset                                                                             "Minutes since reset",
       now()-pg_postmaster_start_time()                                                            "Uptime",
       '-------'                                                                                   "-------------------------------------",
       *
  FROM (
    SELECT checkpoints_timed,
           checkpoints_req,
           checkpoints_timed + checkpoints_req checkpoints,
           checkpoint_sync_time,
           checkpoint_write_time,
           buffers_checkpoint,
           buffers_clean,
           maxwritten_clean,
           buffers_backend,
           buffers_backend_fsync,
           buffers_alloc,
           buffers_checkpoint + buffers_clean + buffers_backend total_buffers,
           pg_postmaster_start_time() startup,
           stats_reset,
           round(extract('epoch' from now() - stats_reset)/60)::numeric min_since_reset,
           delay.setting::numeric bgwriter_delay,
           lru.setting::numeric bgwriter_lru_maxpages,
           ratio.setting::numeric bgwriter_lru_multiplier,
           ckpt_s.setting::numeric max_wal_size,
           ckpt_t.setting::numeric checkpoint_timeout
      FROM pg_stat_bgwriter
      JOIN pg_settings lru   ON lru.name = 'bgwriter_lru_maxpages'
      JOIN pg_settings delay ON delay.name = 'bgwriter_delay'
      JOIN pg_settings ratio ON ratio.name = 'bgwriter_lru_multiplier'
      JOIN pg_settings ckpt_s ON ckpt_s.name = 'max_wal_size'
      JOIN pg_settings ckpt_t ON ckpt_t.name = 'checkpoint_timeout'
        ) bgstats\x\g\x