planner: support Hypo indexes

ddl/ddl_api.go

@@ -6722,6 +6722,28 @@ func (d *ddl) CreateIndex(ctx sessionctx.Context, stmt *ast.CreateIndexStmt) err
 		stmt.IndexPartSpecifications, stmt.IndexOption, stmt.IfNotExists)
 }
 
+// addHypoIndexIntoCtx adds this index as a hypo-index into this ctx.
+func (d *ddl) addHypoIndexIntoCtx(ctx sessionctx.Context, schemaName, tableName model.CIStr, indexInfo *model.IndexInfo) error {
+	sctx := ctx.GetSessionVars()
+	indexName := indexInfo.Name
+
+	if sctx.HypoIndexes == nil {
+		sctx.HypoIndexes = make(map[string]map[string]map[string]*model.IndexInfo)
+	}
+	if sctx.HypoIndexes[schemaName.L] == nil {
+		sctx.HypoIndexes[schemaName.L] = make(map[string]map[string]*model.IndexInfo)
+	}
+	if sctx.HypoIndexes[schemaName.L][tableName.L] == nil {
+		sctx.HypoIndexes[schemaName.L][tableName.L] = make(map[string]*model.IndexInfo)
+	}
+	if _, exist := sctx.HypoIndexes[schemaName.L][tableName.L][indexName.L]; exist {
+		return errors.Trace(errors.Errorf("conflict hypo index name %s", indexName.L))
+	}
+
+	sctx.HypoIndexes[schemaName.L][tableName.L][indexName.L] = indexInfo
+	return nil
+}
+
 func (d *ddl) createIndex(ctx sessionctx.Context, ti ast.Ident, keyType ast.IndexKeyType, indexName model.CIStr,
 	indexPartSpecifications []*ast.IndexPartSpecification, indexOption *ast.IndexOption, ifNotExists bool) error {
 	// not support Spatial and FullText index
@@ -6812,6 +6834,15 @@ func (d *ddl) createIndex(ctx sessionctx.Context, ti ast.Ident, keyType ast.Inde
 		}
 	}
 
+	if indexOption != nil && indexOption.Tp == model.IndexTypeHypo { // for hypo-index
+		indexInfo, err := BuildIndexInfo(ctx, tblInfo.Columns, indexName, false, unique, global,
+			indexPartSpecifications, indexOption, model.StatePublic)
+		if err != nil {
+			return err
+		}
+		return d.addHypoIndexIntoCtx(ctx, ti.Schema, ti.Name, indexInfo)
+	}
+
 	tzName, tzOffset := ddlutil.GetTimeZone(ctx)
 	charset, collate := ctx.GetSessionVars().GetCharsetInfo()
 	job := &model.Job{
@@ -7041,6 +7072,19 @@ func (d *ddl) DropIndex(ctx sessionctx.Context, stmt *ast.DropIndexStmt) error {
 	return err
 }
 
+// dropHypoIndexFromCtx drops this hypo-index from this ctx.
+func (d *ddl) dropHypoIndexFromCtx(ctx sessionctx.Context, schema, table, index model.CIStr) bool {
+	sctx := ctx.GetSessionVars()
+	if sctx.HypoIndexes != nil &&
+		sctx.HypoIndexes[schema.L] != nil &&
+		sctx.HypoIndexes[schema.L][table.L] != nil &&
+		sctx.HypoIndexes[schema.L][table.L][index.L] != nil {
+		delete(sctx.HypoIndexes[schema.L][table.L], index.L)
+		return true
+	}
+	return false
+}
+
 func (d *ddl) dropIndex(ctx sessionctx.Context, ti ast.Ident, indexName model.CIStr, ifExists bool) error {
 	is := d.infoCache.GetLatest()
 	schema, ok := is.SchemaByName(ti.Schema)
@@ -7055,6 +7099,11 @@ func (d *ddl) dropIndex(ctx sessionctx.Context, ti ast.Ident, indexName model.CI
 		return errors.Trace(dbterror.ErrOptOnCacheTable.GenWithStackByArgs("Drop Index"))
 	}
 
+	// try hypo-index first
+	if d.dropHypoIndexFromCtx(ctx, ti.Schema, ti.Name, indexName) {
+		return nil
+	}
+
 	indexInfo := t.Meta().FindIndexByName(indexName.L)
 
 	isPK, err := CheckIsDropPrimaryKey(indexName, indexInfo, t)

executor/show.go

@@ -963,6 +963,10 @@ func getDefaultCollate(charsetName string) string {
 
 // ConstructResultOfShowCreateTable constructs the result for show create table.
 func ConstructResultOfShowCreateTable(ctx sessionctx.Context, tableInfo *model.TableInfo, allocators autoid.Allocators, buf *bytes.Buffer) (err error) {
+	return constructResultOfShowCreateTable(ctx, nil, tableInfo, allocators, buf)
+}
+
+func constructResultOfShowCreateTable(ctx sessionctx.Context, dbName *model.CIStr, tableInfo *model.TableInfo, allocators autoid.Allocators, buf *bytes.Buffer) (err error) {
 	if tableInfo.IsView() {
 		fetchShowCreateTable4View(ctx, tableInfo, buf)
 		return nil
@@ -1109,6 +1113,18 @@ func ConstructResultOfShowCreateTable(ctx sessionctx.Context, tableInfo *model.T
 			publicIndices = append(publicIndices, idx)
 		}
 	}
+
+	// consider hypo-indexes
+	hypoIndexes := ctx.GetSessionVars().HypoIndexes
+	if hypoIndexes != nil && dbName != nil {
+		schemaName := dbName.L
+		tblName := tableInfo.Name.L
+		if hypoIndexes[schemaName] != nil && hypoIndexes[schemaName][tblName] != nil {
+			for _, index := range hypoIndexes[schemaName][tblName] {
+				publicIndices = append(publicIndices, index)
+			}
+		}
+	}
 	if len(publicIndices) > 0 {
 		buf.WriteString(",\n")
 	}
@@ -1142,6 +1158,9 @@ func ConstructResultOfShowCreateTable(ctx sessionctx.Context, tableInfo *model.T
 		if idxInfo.Comment != "" {
 			fmt.Fprintf(buf, ` COMMENT '%s'`, format.OutputFormat(idxInfo.Comment))
 		}
+		if idxInfo.Tp == model.IndexTypeHypo {
+			fmt.Fprintf(buf, ` /* HYPO INDEX */`)
+		}
 		if idxInfo.Primary {
 			if tableInfo.HasClusteredIndex() {
 				buf.WriteString(" /*T![clustered_index] CLUSTERED */")
@@ -1392,7 +1411,7 @@ func (e *ShowExec) fetchShowCreateTable() error {
 	tableInfo := tb.Meta()
 	var buf bytes.Buffer
 	// TODO: let the result more like MySQL.
-	if err = ConstructResultOfShowCreateTable(e.ctx, tableInfo, tb.Allocators(e.ctx), &buf); err != nil {
+	if err = constructResultOfShowCreateTable(e.ctx, &e.DBName, tableInfo, tb.Allocators(e.ctx), &buf); err != nil {
 		return err
 	}
 	if tableInfo.IsView() {

parser/misc.go

@@ -661,6 +661,7 @@ var tokenMap = map[string]int{
 	"ROW":                      row,
 	"ROWS":                     rows,
 	"RTREE":                    rtree,
+	"HYPO":                     hypo,
 	"RESUME":                   resume,
 	"RUN":                      run,
 	"RUNNING":                  running,

parser/model/model.go

@@ -1364,6 +1364,8 @@ func (t IndexType) String() string {
 		return "HASH"
 	case IndexTypeRtree:
 		return "RTREE"
+	case IndexTypeHypo:
+		return "HYPO"
 	default:
 		return ""
 	}
@@ -1375,6 +1377,7 @@ const (
 	IndexTypeBtree
 	IndexTypeHash
 	IndexTypeRtree
+	IndexTypeHypo
 )
 
 // IndexInfo provides meta data describing a DB index.