2) Suppose a company would like to design a data warehouse to facilitate the analysis of objects with RFID tags in an online analytical processing manner. Since recently, the Radio-Frequency Identification (RFID) is commonly used to trace object movement and perform inventory control. (An RFID reader can successfully read an RFID tag from a limited distance at any scheduled time.) The company registers huge amounts of RFID data in the format of (RFID, at location, time), and also has some information about the objects carrying the RFID tag, e. g., (RFID, product name, product category, producer, date produced, price). a) Design a data warehouse using a Star schema to facilitate effective registration and online analytical processing of such data. b) Design the above data warehouse using a snowflake schema. c) Design the above data warehouse using a fact constellation schema. d) (Optional) The RFID data may contain lots of noise, such as missing registration and misreading of IDs. Discuss a method that effectively cleans up the noisy data in the RFID data warehouse. e) (Optional) If a customer returns a jug of milk and complains that it has spoiled before its expiration data, discuss how you could investigate such a case in the warehouse to find out what could be the problem, either in shipping or in storage.