From 30b8f4227f570e1f564c01fda5bdf0eadc19c2b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ji=C5=99=C3=AD=20=C4=8Ctvrtka?= <j.ctvrtka@gmail.com>
Date: Wed, 19 Feb 2025 15:13:46 +0100
Subject: [PATCH] PMM-9288 Remove nScanned completely.

---
 src/go/mongolib/stats/stats.go         | 12 ++++--------
 src/go/pt-mongodb-query-digest/main.go | 12 ++++++------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/src/go/mongolib/stats/stats.go b/src/go/mongolib/stats/stats.go
index e7634448b..29d7bc728 100644
--- a/src/go/mongolib/stats/stats.go
+++ b/src/go/mongolib/stats/stats.go
@@ -270,7 +270,6 @@ func (g GroupKey) String() string {
 
 type totalCounters struct {
 	Count                                      int
-	Scanned                                    float64
 	Returned                                   float64
 	QueryTime                                  float64
 	Bytes                                      float64
@@ -298,7 +297,6 @@ type QueryStats struct {
 	ResponseLengthCount int
 	ResponseLength      Statistics
 	Returned            Statistics
-	Scanned             Statistics
 
 	PlanSummary       string
 	CollScanCount     int
@@ -376,9 +374,6 @@ func countersToStats(query QueryInfoAndCounters, uptime int64, tc totalCounters)
 		StorageTimeReadingMicrosCount:                   len(query.StorageTimeReadingMicros),
 		StorageTimeReadingMicros:                        calcStats(query.StorageTimeReadingMicros),
 	}
-	if tc.Scanned > 0 {
-		queryStats.Scanned.Pct = queryStats.Scanned.Total * 100 / tc.Scanned
-	}
 	if tc.Returned > 0 {
 		queryStats.Returned.Pct = queryStats.Returned.Total * 100 / tc.Returned
 	}
@@ -388,9 +383,6 @@ func countersToStats(query QueryInfoAndCounters, uptime int64, tc totalCounters)
 	if tc.Bytes > 0 {
 		queryStats.ResponseLength.Pct = queryStats.ResponseLength.Total * 100 / tc.Bytes
 	}
-	if queryStats.Returned.Total > 0 {
-		queryStats.Ratio = queryStats.Scanned.Total / queryStats.Returned.Total
-	}
 	if tc.DocsExamined > 0 {
 		queryStats.DocsExamined.Pct = queryStats.DocsExamined.Total * 100 / tc.DocsExamined
 	}
@@ -460,6 +452,10 @@ func calcTotalCounters(queries []QueryInfoAndCounters) totalCounters {
 }
 
 func calcStats(samples []float64) Statistics {
+	if len(samples) == 0 {
+		return Statistics{}
+	}
+
 	var s Statistics
 	s.Total, _ = stats.Sum(samples)
 	s.Min, _ = stats.Min(samples)
diff --git a/src/go/pt-mongodb-query-digest/main.go b/src/go/pt-mongodb-query-digest/main.go
index badc1a57e..5809fc752 100644
--- a/src/go/pt-mongodb-query-digest/main.go
+++ b/src/go/pt-mongodb-query-digest/main.go
@@ -497,23 +497,23 @@ func sortQueries(queries []stats.QueryStats, orderby []string) []stats.QueryStat
 			}
 
 		//
-		case "docs-scanned":
+		case "docs-examined":
 			f = func(c1, c2 *stats.QueryStats) bool {
-				return c1.Scanned.Max < c2.Scanned.Max
+				return c1.DocsExamined.Max < c2.DocsExamined.Max
 			}
-		case "-docs-scanned":
+		case "-docs-examined":
 			f = func(c1, c2 *stats.QueryStats) bool {
-				return c1.Scanned.Max > c2.Scanned.Max
+				return c1.DocsExamined.Max > c2.DocsExamined.Max
 			}
 
 		//
 		case "docs-returned":
 			f = func(c1, c2 *stats.QueryStats) bool {
-				return c1.Returned.Max < c2.Scanned.Max
+				return c1.Returned.Max < c2.DocsExamined.Max
 			}
 		case "-docs-returned":
 			f = func(c1, c2 *stats.QueryStats) bool {
-				return c1.Returned.Max > c2.Scanned.Max
+				return c1.Returned.Max > c2.DocsExamined.Max
 			}
 		}
 		// count,query-time,docs-scanned, docs-returned. - in front of the field name denotes reverse order.")