diff --git a/Dockerfile b/Dockerfile
index 86128d41a..7d17c9266 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,6 @@
-FROM debian:7.11-slim
+FROM debian:10-slim
 RUN useradd -u 20001 postgres_exporter
 
-FROM scratch
-
-COPY --from=0 /etc/passwd /etc/passwd
 USER postgres_exporter
 
 ARG binary
diff --git a/README.md b/README.md
index a81bcd9b2..8864b88c4 100644
--- a/README.md
+++ b/README.md
@@ -94,8 +94,9 @@ The following environment variables configure the exporter:
   URI may contain the username and password to connect with.
 
 * `DATA_SOURCE_URI`
-   an alternative to `DATA_SOURCE_NAME` which exclusively accepts the raw URI
-   without a username and password component.
+   an alternative to `DATA_SOURCE_NAME` which exclusively accepts the hostname
+   without a username and password component. For example, `my_pg_hostname` or
+   `my_pg_hostname?sslmode=disable`.
 
 * `DATA_SOURCE_URI_FILE`
    The same as above but reads the URI from a file.
diff --git a/cmd/postgres_exporter/postgres_exporter.go b/cmd/postgres_exporter/postgres_exporter.go
index 6f2c2b71d..ab6124bca 100644
--- a/cmd/postgres_exporter/postgres_exporter.go
+++ b/cmd/postgres_exporter/postgres_exporter.go
@@ -542,7 +542,7 @@ func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[str
 func addQueries(content []byte, pgVersion semver.Version, server *Server) error {
 	metricMaps, newQueryOverrides, err := parseUserQueries(content)
 	if err != nil {
-		return nil
+		return err
 	}
 	// Convert the loaded metric map into exporter representation
 	partialExporterMap := makeDescMap(pgVersion, server.labels, metricMaps)
diff --git a/example.alerts.yml b/example.alerts.yml
index 1b08a437f..ff3d75a7f 100644
--- a/example.alerts.yml
+++ b/example.alerts.yml
@@ -3,7 +3,7 @@ groups:
   - name: PostgreSQL
     rules:
     - alert: PostgreSQLMaxConnectionsReached
-      expr: sum(pg_stat_activity_count) by (instance) > sum(pg_settings_max_connections) by (instance)
+      expr: sum(pg_stat_activity_count) by (instance) >= sum(pg_settings_max_connections) by (instance) - sum(pg_settings_superuser_reserved_connections) by (instance)
       for: 1m
       labels:
         severity: email
@@ -12,7 +12,7 @@ groups:
         description: "{{ $labels.instance }} is exceeding the currently configured maximum Postgres connection limit (current value: {{ $value }}s). Services may be degraded - please take immediate action (you probably need to increase max_connections in the Docker image and re-deploy."
 
     - alert: PostgreSQLHighConnections
-      expr: sum(pg_stat_activity_count) by (instance) > sum(pg_settings_max_connections * 0.8) by (instance)
+      expr: sum(pg_stat_activity_count) by (instance) > (sum(pg_settings_max_connections) by (instance) - sum(pg_settings_superuser_reserved_connections) by (instance)) * 0.8
       for: 10m
       labels:
         severity: email
diff --git a/magefile.go b/magefile.go
index b3e0992f8..eedd529d6 100644
--- a/magefile.go
+++ b/magefile.go
@@ -97,6 +97,7 @@ func (p *Platform) ReleaseBase() string {
 var platforms []Platform = []Platform{
 	{"linux", "amd64", ""},
 	{"linux", "386", ""},
+	{"linux", "arm64", ""},
 	{"darwin", "amd64", ""},
 	{"darwin", "386", ""},
 	{"windows", "amd64", ".exe"},
diff --git a/queries.yaml b/queries.yaml
index db2c0680b..76a91245d 100644
--- a/queries.yaml
+++ b/queries.yaml
@@ -122,7 +122,7 @@ pg_statio_user_tables:
         description: "Number of buffer hits in this table's TOAST table indexes (if any)"
         
 pg_database:
-  query: "SELECT pg_database.datname, pg_database_size(pg_database.datname) as size FROM pg_database"
+  query: "SELECT pg_database.datname, pg_database_size(pg_database.datname) as size_bytes FROM pg_database"
   master: true
   cache_seconds: 30
   metrics: