code: func replaceColsInPropBySchema(prop *requiredProperty, schema expression.Schema) *requiredProperty {
  	newProps := make([]*columnProp, 0, len(prop.props))
  	for _, p := range prop.props {
  		idx := schema.GetColumnIndex(p.col)
  		if idx == -1 {
  			log.Printf("Can't find column %s in schema", p.col)
  		}
  		newProps = append(newProps, &columnProp{col: schema.Columns[idx], desc: p.desc})
  	}
  	return &requiredProperty{
  		props:      newProps,
  		sortKeyLen: prop.sortKeyLen,
  		limit:      prop.limit,
  	}
  }
docs: // replaceColsInPropBySchema replaces the columns in original prop with the columns in schema.