feat: add "HISTOGRAM" option in "ALTER TABLE... UPDATE/DROP..." (ping…

…cap#925)

ast/stats.go

@@ -37,6 +37,9 @@ type AnalyzeTableStmt struct {
 	// IndexFlag is true when we only analyze indices for a table.
 	IndexFlag   bool
 	Incremental bool
+	// HistogramOperation is set in "ANALYZE TABLE ... UPDATE/DROP HISTOGRAM ..." statement.
+	HistogramOperation HistogramOperationType
+	ColumnNames        []*ColumnName
 }
 
 // AnalyzeOptType is the type for analyze options.
@@ -60,6 +63,28 @@ var AnalyzeOptionString = map[AnalyzeOptionType]string{
 	AnalyzeOptNumSamples:    "SAMPLES",
 }
 
+// HistogramOperationType is the type for histogram operation.
+type HistogramOperationType int
+
+// Histogram operation types.
+const (
+	// HistogramOperationNop shows no operation in histogram. Default value.
+	HistogramOperationNop HistogramOperationType = iota
+	HistogramOperationUpdate
+	HistogramOperationDrop
+)
+
+// String implements fmt.Stringer for HistogramOperationType.
+func (hot HistogramOperationType) String() string {
+	switch hot {
+	case HistogramOperationUpdate:
+		return "UPDATE HISTOGRAM"
+	case HistogramOperationDrop:
+		return "DROP HISTOGRAM"
+	}
+	return ""
+}
+
 // AnalyzeOpt stores the analyze option type and value.
 type AnalyzeOpt struct {
 	Type  AnalyzeOptionType
@@ -90,6 +115,20 @@ func (n *AnalyzeTableStmt) Restore(ctx *format.RestoreCtx) error {
 		}
 		ctx.WriteName(partition.O)
 	}
+	if n.HistogramOperation != HistogramOperationNop {
+		ctx.WritePlain(" ")
+		ctx.WriteKeyWord(n.HistogramOperation.String())
+		ctx.WritePlain(" ")
+	}
+	if len(n.ColumnNames) > 0 {
+		ctx.WriteKeyWord("ON ")
+		for i, columnName := range n.ColumnNames {
+			if i != 0 {
+				ctx.WritePlain(",")
+			}
+			ctx.WriteName(columnName.Name.O)
+		}
+	}
 	if n.IndexFlag {
 		ctx.WriteKeyWord(" INDEX")
 	}

misc.go

@@ -352,6 +352,7 @@ var tokenMap = map[string]int{
 	"HAVING":                   having,
 	"HIGH_PRIORITY":            highPriority,
 	"HISTORY":                  history,
+	"HISTOGRAM":                histogram,
 	"HOSTS":                    hosts,
 	"HOUR_MICROSECOND":         hourMicrosecond,
 	"HOUR_MINUTE":              hourMinute,