code: func doDDLWorks(s Session) {
  	// Create a test database.
  	mustExecute(s, "CREATE DATABASE IF NOT EXISTS test")
  	// Create system db.
  	mustExecute(s, fmt.Sprintf("CREATE DATABASE IF NOT EXISTS %s;", mysql.SystemDB))
  	// Create user table.
  	mustExecute(s, CreateUserTable)
  	// Create privilege tables.
  	mustExecute(s, CreateDBPrivTable)
  	mustExecute(s, CreateTablePrivTable)
  	mustExecute(s, CreateColumnPrivTable)
  	// Create global system variable table.
  	mustExecute(s, CreateGloablVariablesTable)
  	// Create TiDB table.
  	mustExecute(s, CreateTiDBTable)
  	// Create help table.
  	mustExecute(s, CreateHelpTopic)
  	// Create stats_meta table.
  	mustExecute(s, CreateStatsMetaTable)
  	// Create stats_columns table.
  	mustExecute(s, CreateStatsColsTable)
  	// Create stats_buckets table.
  	mustExecute(s, CreateStatsBucketsTable)
  	// Create gc_delete_range table.
  	mustExecute(s, CreateGCDeleteRangeTable)
  	// Create gc_delete_range_done table.
  	mustExecute(s, CreateGCDeleteRangeDoneTable)
  	// Create stats_feedback table.
  	mustExecute(s, CreateStatsFeedbackTable)
  	// Create role_edges table.
  	mustExecute(s, CreateRoleEdgesTable)
  	// Create default_roles table.
  	mustExecute(s, CreateDefaultRolesTable)
  	// Create bind_info table.
  	mustExecute(s, CreateBindInfoTable)
  	// Create stats_topn_store table.
  	mustExecute(s, CreateStatsTopNTable)
  }
docs: // doDDLWorks executes DDL statements in bootstrap stage.