(1)Data Integration Data Source A Wrapper Data Source B Wrapper Mediated Schema “Virtual Database” Data Source C Wrapper Fig.1 Simple schematic for a data- integration solution.A system designer constructs a mediated schema against which users can run queries. 11 Copyright 2019 by Xiaoyu Li.Copyright © 2019 by Xiaoyu Li. 11 (1) Data Integration Fig.1 Simple schematic for a data￾integration solution. A system designer constructs a mediated schema against which users can run queries