Copyright© 2014, Sira Yongchareon Department of Computing, Faculty of Creative Industries and Business Lecturer : Dr. Sira Yongchareon ISCG 6425 Data Warehousing (DW) Week 1 Introduction to Data Warehousing

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 2 Course’s introduction Introduction to Data Warehousing (DW) SQL & database concepts revision Outline

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 3 Course’s introduction About our classes  3 hours/week  Lecture then Lab session, mins mid-break  Workshop mode (practical), break at anytime  Attendance and homework will be checked and marked   Elena (Teaching assistance) take care lab sessions & all the markings.. Be nice to her.

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 4 Course’s introduction About assessments  No Final Exam!!! Yeah  2 x Assignments : 60%  Individual 30% (including attendance + worksheet + interview)  Interviews required to pass the assignment!!!  Final Test (Theory) : 40% (at Week 13) How to pass this subject  Obtain scores 50% from the overall

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 5 Course’s introduction Learning resources  Lecture slides, tutorials, worksheets, lab exercises, text books  All books can be accessed through Unitec’s library ( e-book )

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 6 Course’s introduction Outside-a-class contact  me  code of conduct  In the subject line of your , please write “ [DW] ” followed by “ your topic/question/issue ”.  For example,  To :  Subject : [ DW ] Question about the next week’s test  WARNING!! Without following that your may be directed to my “ very low priority mailbox ”

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 7 Any questions about the course?

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 8 Introduction to Data Warehousing(DW) What is a Data Warehouse? (Wikipedia)  DW is a database used for reporting and data analysis  DW is a central repository of data which is created by integrating data from one or more disparate sources  DW stores current as well as historical data that are used for creating reports to support decision makers in an organization  Business Intelligence

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 9 DW to support “ decision makers ”

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 10 The flow of data in DW system

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 11 From Data to Knowledge

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 12 OLTP ( O n- L ine T ransaction P rocessing) Databases  Database designed for day-to-day operations / transactions  Queries contain SELECT, INSERT, UPDATE, DELETE  Normalized schema (no duplicates, no inconsistency data) OLAP ( O n- L ine A nalytical P rocessing) Database  Database designed for business analytics, summary reports, decision making  Queries have SELECT only (no INSERT, DELETE, UPDATE)  De-normalized schema (lots of duplicates/redundancies) OLTP vs. OLAP Databases

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 13 OLTP vs. OLAP Databases Topic OLTP DatabasesOLAP Databases Application Operational system : ERP, CRM, Legacy applications Management Information System, Decision Support System Typical users Staffs, day-to-day operation staffsManagers, Executives What the data Reveals a snapshot of on-going business processes Multi-dimensional views of various kinds of business activities Inserts and Updates Short and fast inserts and updates initiated by end users Periodic long-running batch jobs refresh the data Queries Relatively standardized and simple queries Returning relatively few records Often complex queries involving aggregations

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 14 OLTP vs. OLAP Databases (cont.) Topic OLTP DatabasesOLAP Databases Processing Speed Typically very fast Depends on the amount of data involved; batch and complex queries may take many hours; query speed can be improved by creating indexes Space Requirement Can be relatively small if historical data is archived Larger due to the existence of aggregation structures and history data; requires more indexes than OLTP Database Design Highly normalized with many tables Typically de-normalized with fewer tables; use of star and/or snowflake schemas Backup and Recovery Backup religiously; operational data is critical to run the business, data loss is likely to entail significant monetary loss and legal liability Instead of regular backups, some environments may consider simply reloading the OLTP data as a recovery method

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 15 Our lab has MS-SQL Server 2008 R2 installed. If you want to download and install it on your computer.  Google “unitec dreamspark” (Microsoft for academia)  Register first then you can download any MS software  Choose SQL Enterprise 2014 (latest version) Software used in this course

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 16 Prerequisite knowledge Database concepts, explain what are the followings..  ERD, Relational Schema, and Normalization  SQL  DDL : Create, Drop, Alter  DML : Select, Insert, Update, Delete  PK, FK, Composite Key, Null value, Constraints  Union, Join (Inner and Outer), Having, Group by, Order by  Count, Sum, Avg, Min, Max  Sub-query Please DO self study if you don’t know any of them

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 17 How much do you understand ERD? 1. How to read this ERD? 2. Convert this ERD to a Relational Schema (Database tables)

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 18 How much do you understand ERD 2? 1. How to read this ERD? 2. Convert this ERD to a Relational Schema (Database tables)

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 19 How much do you understand SQL? SELECT Name FROM Orders, Salesperson WHERE Orders.salesperson_id = Salesperson.ID GROUP BY salesperson_id HAVING COUNT ( salesperson_id ) >1 Anything wrong??

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 20 Are you prepared for the course? Next week will have a “ Hurdle Test” !!!  Multiple-choice questions  no code writing but understanding codes is required  To test if you are READY for this course ** You MUST PASS in order to continue the course **

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 21 Are you prepared for the course? Test topics include:  Relational Databases and SQL concepts  Relations, Keys and Normalization  Basic + Intermediate SQL commands Study resources - PLEASE DO YOUR OWN STUDY!    And from your Lv.5 Introduction to Databases paper

ISCG6425 Data Warehousing (by Sira Yongchareon) Department of Computing, Faculty of Creative Industries and Business 22 Any questions?