Add MAX_DURATION option support for CREATE INDEX

- Add MaxDurationOption AST type for resumable index operations
- Parse MAX_DURATION = value [MINUTES] in index options
- Add JSON marshaling for MaxDurationOption

Author: claude

ast/alter_table_alter_index_statement.go

@@ -53,3 +53,13 @@ type OrderIndexOption struct {
 
 func (o *OrderIndexOption) indexOption() {}
 func (o *OrderIndexOption) node()        {}
+
+// MaxDurationOption represents MAX_DURATION option for resumable index operations
+type MaxDurationOption struct {
+	MaxDuration ScalarExpression
+	Unit        string // "", "Minutes"
+	OptionKind  string // "MaxDuration"
+}
+
+func (m *MaxDurationOption) indexOption() {}
+func (m *MaxDurationOption) node()        {}

parser/marshal.go

@@ -10809,6 +10809,18 @@ func indexOptionToJSON(opt ast.IndexOption) jsonNode {
 			node["Expression"] = scalarExpressionToJSON(o.Expression)
 		}
 		return node
+	case *ast.MaxDurationOption:
+		node := jsonNode{
+			"$type":      "MaxDurationOption",
+			"OptionKind": o.OptionKind,
+		}
+		if o.MaxDuration != nil {
+			node["MaxDuration"] = scalarExpressionToJSON(o.MaxDuration)
+		}
+		if o.Unit != "" {
+			node["Unit"] = o.Unit
+		}
+		return node
 	default:
 		return jsonNode{"$type": "UnknownIndexOption"}
 	}

parser/parse_statements.go

@@ -8348,6 +8348,18 @@ func (p *Parser) parseCreateIndexOptions() []ast.IndexOption {
 				OptionKind: "MaxDop",
 				Expression: &ast.IntegerLiteral{LiteralType: "Integer", Value: valueToken.Literal},
 			})
+		case "MAX_DURATION":
+			// Parse MAX_DURATION = value [MINUTES]
+			opt := &ast.MaxDurationOption{
+				OptionKind:  "MaxDuration",
+				MaxDuration: &ast.IntegerLiteral{LiteralType: "Integer", Value: valueToken.Literal},
+			}
+			// Check for optional MINUTES unit
+			if strings.ToUpper(p.curTok.Literal) == "MINUTES" {
+				opt.Unit = "Minutes"
+				p.nextToken() // consume MINUTES
+			}
+			options = append(options, opt)
 		default:
 			// Generic handling for other options
 			if valueStr == "ON" || valueStr == "OFF" {

parser/testdata/Baselines150_CreateIndexStatementTests150/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}

parser/testdata/CreateIndexStatementTests150/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}