diff --git a/smf/clickhouse/config.xml b/smf/clickhouse/config.xml
index 352023300a5..ed69518db69 100644
--- a/smf/clickhouse/config.xml
+++ b/smf/clickhouse/config.xml
@@ -13,6 +13,28 @@
         <flush_interval_milliseconds>10000</flush_interval_milliseconds>
     </query_log>
 
+    <!--
+        Mask long queries generated by oximeter.
+
+        As of this writing, oximeter builds queries like
+
+            SELECT * FROM oximeter.measurements_* WHERE timeseries_key IN (...)
+
+        where the IN clause contains thousands of elements. A single oximeter
+        query can generate multiple queries of this form. We observe that
+        these queries comprise ~80% of the `system.query_log` table, which is
+        itself one of the largest tables in terms of compressed disk use.
+        This block truncates this long query pattern, since it's not
+        operationally useful and consumes a significant amount of disk.
+    -->
+    <query_masking_rules>
+        <rule>
+            <name>truncate large timeseries_key IN clauses</name>
+            <regexp>(\btimeseries_key\s+IN\s*\()[^)]{120,}\)</regexp>
+            <replace>\1...)</replace>
+        </rule>
+    </query_masking_rules>
+
     <metric_log>
         <database>system</database>
         <table>metric_log</table>