diff --git a/pgmon-metrics.cfg b/pgmon-metrics.cfg
index c919530..1f6e799 100644
--- a/pgmon-metrics.cfg
+++ b/pgmon-metrics.cfg
@@ -1,6 +1,6 @@
 # Discovery metrics
-metric=discover_dbs:set::SELECT datname, $1 AS agent, $2 AS cluster FROM pg_database
-metric=discover_rep:set::SELECT client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') AS repid, client_addr, state, $1 AS agent, $2 AS cluster FROM pg_stat_replication
+metric=discover_dbs:set::SELECT datname, %s AS agent, %s AS cluster FROM pg_database
+metric=discover_rep:set::SELECT client_addr || '_' || regexp_replace(application_name, '[ ,]', '_', 'g') AS repid, client_addr, state, %s AS agent, %s AS cluster FROM pg_stat_replication
 
 # Cluster-wide metrics
 metric=version:value::SHOW server_version_num
diff --git a/pgmon.py b/pgmon.py
index 666b432..5dd50be 100755
--- a/pgmon.py
+++ b/pgmon.py
@@ -1235,8 +1235,10 @@ class Worker(threading.Thread):
             # Get any positional query args
             try:
                 pos_args = req.args['pos'].split(':')
+                logger.debug("Found positional args for {}: {}".format(req.metric_name, ','.join(pos_args)))
             except KeyError:
                 pos_args = []
+                logger.debug("No positional args found for {}".format(req.metric_name))
 
             # Query the database
             try: