Fixes broken postgresql dashboard queries (#277)

Author: cjohnston1158

src/grafana_dashboards/postgresql-metrics.json

@@ -2667,35 +2667,35 @@
       "steppedLine": false,
       "targets": [
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_backend{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_backend_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_backend",
           "refId": "A"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_alloc{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_alloc_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_alloc",
           "refId": "B"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_backend_fsync{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_backend_fsync_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "backend_fsync",
           "refId": "C"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_checkpoint{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_checkpoint_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_checkpoint",
           "refId": "D"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_buffers_clean{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_buffers_clean_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "buffers_clean",
@@ -2973,14 +2973,14 @@
       "steppedLine": false,
       "targets": [
         {
-          "expr": "irate(pg_stat_bgwriter_checkpoint_write_time{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_checkpoint_write_time_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "write_time - Total amount of time that has been spent in the portion of checkpoint processing where files are written to disk.",
           "refId": "B"
         },
         {
-          "expr": "irate(pg_stat_bgwriter_checkpoint_sync_time{instance=\"$instance\"}[5m])",
+          "expr": "irate(pg_stat_bgwriter_checkpoint_sync_time_total{instance=\"$instance\"}[5m])",
           "format": "time_series",
           "intervalFactor": 1,
           "legendFormat": "sync_time - Total amount of time that has been spent in the portion of checkpoint processing where files are synchronized to disk.",