A simple query

ql/ql/src/codeql_ql/StructuredLogs.qll

@@ -210,6 +210,8 @@ module KindPredicatesLog {
 
     AppearsAs getAppearsAs() { result = this.getObject("appearsAs") }
 
+    int getMillis() { result = this.getNumber("millis") }
+
     predicate hasCompletionTime(
       int year, string month, int day, int hours, int minute, int second, int millisecond
     ) {
@@ -228,6 +230,12 @@ module KindPredicatesLog {
     }
 
     float getResultSize() { result = this.getFloat("resultSize") }
+
+    override string toString() {
+      if exists(this.getPredicateName())
+      then result = getPredicateName()
+      else result = "<Summary event>"
+    }
   }
 
   class SentinelEmpty extends SummaryEvent {

ql/ql/src/experimental/queries/SlowPredicates.ql

@@ -0,0 +1,15 @@
+/**
+ * Shows a list of the "slow" predicates by wallclock time.
+ */
+
+import ql
+import codeql_ql.StructuredLogs
+
+int predicateRank(KindPredicatesLog::SummaryEvent evt) {
+  evt =
+    rank[result](KindPredicatesLog::ComputeSimple y, int m | m = y.getMillis() | y order by m desc)
+}
+
+from KindPredicatesLog::SummaryEvent evt
+where predicateRank(evt) < 50
+select evt, evt.getMillis() as time order by time desc