*: replace compareDatum by compare (#30048)

executor/analyze_test.go

@@ -371,7 +371,7 @@ func (s *testFastAnalyze) TestAnalyzeFastSample(c *C) {
 		samples := mockExec.Collectors[i].Samples
 		c.Assert(len(samples), Equals, 20)
 		for j := 1; j < 20; j++ {
-			cmp, err := samples[j].Value.CompareDatum(tk.Se.GetSessionVars().StmtCtx, &samples[j-1].Value)
+			cmp, err := samples[j].Value.Compare(tk.Se.GetSessionVars().StmtCtx, &samples[j-1].Value, collate.GetBinaryCollator())
 			c.Assert(err, IsNil)
 			c.Assert(cmp, Greater, 0)
 		}
@@ -381,15 +381,15 @@ func (s *testFastAnalyze) TestAnalyzeFastSample(c *C) {
 func checkHistogram(sc *stmtctx.StatementContext, hg *statistics.Histogram) (bool, error) {
 	for i := 0; i < len(hg.Buckets); i++ {
 		lower, upper := hg.GetLower(i), hg.GetUpper(i)
-		cmp, err := upper.CompareDatum(sc, lower)
+		cmp, err := upper.Compare(sc, lower, collate.GetBinaryCollator())
 		if cmp < 0 || err != nil {
 			return false, err
 		}
 		if i == 0 {
 			continue
 		}
 		previousUpper := hg.GetUpper(i - 1)
-		cmp, err = lower.CompareDatum(sc, previousUpper)
+		cmp, err = lower.Compare(sc, previousUpper, collate.GetBinaryCollator())
 		if cmp <= 0 || err != nil {
 			return false, err
 		}

statistics/builder.go

@@ -23,6 +23,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/codec"
+	"github.com/pingcap/tidb/util/collate"
 )
 
 // SortedBuilder is used to build histograms for PK and index.
@@ -67,7 +68,7 @@ func (b *SortedBuilder) Iterate(data types.Datum) error {
 		b.hist.NDV = 1
 		return nil
 	}
-	cmp, err := b.hist.GetUpper(int(b.bucketIdx)).CompareDatum(b.sc, &data)
+	cmp, err := b.hist.GetUpper(int(b.bucketIdx)).Compare(b.sc, &data, collate.GetBinaryCollator())
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -158,7 +159,7 @@ func buildHist(sc *stmtctx.StatementContext, hg *Histogram, samples []*SampleIte
 	hg.AppendBucket(&samples[0].Value, &samples[0].Value, int64(sampleFactor), int64(ndvFactor))
 	for i := int64(1); i < sampleNum; i++ {
 		corrXYSum += float64(i) * float64(samples[i].Ordinal)
-		cmp, err := hg.GetUpper(bucketIdx).CompareDatum(sc, &samples[i].Value)
+		cmp, err := hg.GetUpper(bucketIdx).Compare(sc, &samples[i].Value, collate.GetBinaryCollator())
 		if err != nil {
 			return 0, errors.Trace(err)
 		}

util/collate/collate.go

@@ -154,6 +154,11 @@ func GetCollator(collate string) Collator {
 	return binCollatorInstance
 }
 
+// GetBinaryCollator gets the binary collator, it is often used when we want to apply binary compare.
+func GetBinaryCollator() Collator {
+	return binCollatorInstance
+}
+
 // GetCollatorByID get the collator according to id, it will return the binary collator if the corresponding collator doesn't exist.
 func GetCollatorByID(id int) Collator {
 	if atomic.LoadInt32(&newCollationEnabled) == 1 {