stats: fix panic when log detailed stats info (#7588)

pingcap · Sep 3, 2018 · aa9f46a · aa9f46a
1 parent e0b98a3
commit aa9f46a
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Showing 2 changed files with 16 additions and 5 deletions.
diff --git a/statistics/feedback.go b/statistics/feedback.go
@@ -844,16 +844,20 @@ func logForIndex(prefix string, t *Table, idx *Index, ranges []*ranger.Range, ac
 		}
 		colName := idx.Info.Columns[rangePosition].Name.L
 		// prefer index stats over column stats
-		if idxHist := t.indexStartWithColumnForDebugLog(colName); idxHist != nil {
+		if idxHist := t.indexStartWithColumnForDebugLog(colName); idxHist != nil && idxHist.Histogram.Len() > 0 {
 			rangeString := logForIndexRange(idxHist, &rang, -1, factor)
 			log.Debugf("%s index: %s, actual: %d, equality: %s, expected equality: %d, %s", prefix, idx.Info.Name.O,
 				actual[i], equalityString, equalityCount, rangeString)
-		} else if colHist := t.columnByNameForDebugLog(colName); colHist != nil {
+		} else if colHist := t.columnByNameForDebugLog(colName); colHist != nil && colHist.Histogram.Len() > 0 {
 			rangeString := colRangeToStr(colHist, &rang, -1, factor)
 			log.Debugf("%s index: %s, actual: %d, equality: %s, expected equality: %d, %s", prefix, idx.Info.Name.O,
 				actual[i], equalityString, equalityCount, rangeString)
 		} else {
-			return
+			count, err := getPseudoRowCountByColumnRanges(sc, float64(t.Count), []*ranger.Range{&rang}, 0)
+			if err == nil {
+				log.Debugf("%s index: %s, actual: %d, equality: %s, expected equality: %d, range: %s, pseudo count: %.0f", prefix, idx.Info.Name.O,
+					actual[i], equalityString, equalityCount, rang.String(), count)
+			}
 		}
 	}
 }

diff --git a/statistics/update_test.go b/statistics/update_test.go
@@ -869,23 +869,26 @@ func (s *testStatsUpdateSuite) TestLogDetailedInfo(c *C) {
 	oriMinError := statistics.MinLogErrorRate
 	oriLevel := log.GetLevel()
 	oriBucketNum := executor.GetMaxBucketSizeForTest()
+	oriLease := s.do.StatsHandle().Lease
 	defer func() {
 		statistics.FeedbackProbability = oriProbability
 		statistics.MinLogScanCount = oriMinLogCount
 		statistics.MinLogErrorRate = oriMinError
 		executor.SetMaxBucketSizeForTest(oriBucketNum)
+		s.do.StatsHandle().Lease = oriLease
 		log.SetLevel(oriLevel)
 	}()
 	executor.SetMaxBucketSizeForTest(4)
 	statistics.FeedbackProbability = 1
 	statistics.MinLogScanCount = 0
 	statistics.MinLogErrorRate = 0
+	s.do.StatsHandle().Lease = 1
 
 	testKit := testkit.NewTestKit(c, s.store)
 	testKit.MustExec("use test")
-	testKit.MustExec("create table t (a bigint(64), b bigint(64), primary key(a), index idx(b), index idx_ba(b,a))")
+	testKit.MustExec("create table t (a bigint(64), b bigint(64), c bigint(64), primary key(a), index idx(b), index idx_ba(b,a), index idx_bc(b,c))")
 	for i := 0; i < 20; i++ {
-		testKit.MustExec(fmt.Sprintf("insert into t values (%d, %d)", i, i))
+		testKit.MustExec(fmt.Sprintf("insert into t values (%d, %d, %d)", i, i, i))
 	}
 	testKit.MustExec("analyze table t")
 	tests := []struct {
@@ -906,6 +909,10 @@ func (s *testStatsUpdateSuite) TestLogDetailedInfo(c *C) {
 			sql:    "select b from t use index(idx_ba) where b = 1 and a <= 5",
 			result: "[stats-feedback] test.t, index: idx_ba, actual: 1, equality: 1, expected equality: 1, range: [-inf,6], actual: -1, expected: 6, buckets: {num: 8 lower_bound: 0 upper_bound: 7 repeats: 1}",
 		},
+		{
+			sql:    "select b from t use index(idx_bc) where b = 1 and c <= 5",
+			result: "[stats-feedback] test.t, index: idx_bc, actual: 1, equality: 1, expected equality: 1, range: [-inf,6], pseudo count: 7",
+		},
 		{
 			sql:    "select b from t use index(idx_ba) where b = 1",
 			result: "[stats-feedback] test.t, index: idx_ba, value: 1, actual: 1, expected: 1",