diff --git a/queries.yaml b/queries.yaml
index 35b75431..1102da44 100644
--- a/queries.yaml
+++ b/queries.yaml
@@ -158,6 +158,7 @@ pg_database:
         usage: "GAUGE"
         description: "Disk space used by the database"
 
+# WARNING: This set of metrics can be very expensive on a busy server as every unique query executed will create an additional time series
 pg_stat_statements:
   query: "SELECT t2.rolname, t3.datname, queryid, calls, total_time / 1000 as total_time_seconds, min_time / 1000 as min_time_seconds, max_time / 1000 as max_time_seconds, mean_time / 1000 as mean_time_seconds, stddev_time / 1000 as stddev_time_seconds, rows, shared_blks_hit, shared_blks_read, shared_blks_dirtied, shared_blks_written, local_blks_hit, local_blks_read, local_blks_dirtied, local_blks_written, temp_blks_read, temp_blks_written, blk_read_time / 1000 as blk_read_time_seconds, blk_write_time / 1000 as blk_write_time_seconds FROM pg_stat_statements t1 JOIN pg_roles t2 ON (t1.userid=t2.oid) JOIN pg_database t3 ON (t1.dbid=t3.oid) WHERE t2.rolname != 'rdsadmin'"
   master: true