1. Zhangxi Lin Texas Tech University ISQS 6347, Data & Text Mining 1 ISQS 6339 Data Management and Business Intelligence Database Review

2. Attributes of Data Sharable. Moveable. Secure. Accurate. Timely. Relevant.

3. Data hierarchy Bits. Characters. Fields (columns). Records (rows). Files (table). Database.

4. Why Build a Database? Handle large amounts of data. Satisfy multiple users. Make information retrieval faster. Make data input faster. Provide greater accuracy.

5. Database versus Database Management System (DBMS) Database is a self-describing collection of integrated files. A DBMS is a complex computer program that acts as a data librarian, supervising the transfer of data between the end user and the database.

6. Relational Model Relation? Attribute? Tuple? Keys.  Primary and foreign. Referential integrity. Relational algebra. Relational Calculus.

7. Relational DB Rules Every row must have exactly the same number of columns (fields or attributes). Each row can have only one value stored in each column (fields or attributes). A column must contain the same kind of value in every row of that column. No two rows can be exactly the same. The order of the rows or of the columns can’t be used to provide information.

8. Terminology Data Processing Informal Relational DB Formal Relational DB File Table Relation RecordRowTuple FieldColumnAttribute

9. Normalization Purpose:  Avoid anomalies. Not delete something you wish to keep while deleting something you do not want to keep. Not having to add something that is unnecessary while adding something that is necessary.  Reduce redundancy. Process:  Successive application of rules.  Bottom-up (data drives process).  Move from first through fifth normal form.  Does it make more or less tables?

11. Entity Relationship Modeling List the entities or objects in the environment.  People, things, transactions. Describe the relationship between them  A single row in table A can be related to how many rows in table B (one or many).  A single row in table B can be related to how many rows in table A (one or many).

12. Example E/RD

13. SQL Definition (DDL).  CREATE, ALTER, DROP. Manipulation (DML).  SELECT, INSERT, UPDATE, DELETE. The most used SQL command  SELECT

14. General Format of SELECT SELECT [DISTINCT] item(s) FROM table(s) [WHERE condition] [GROUP BY columns] [HAVING condition] [ORDER BY row(s)]

15. ISQS 6347, Data & Text Mining 15 Case Study - IMW

16. Want a house? Find one from the web  Up to 50% of prospective American homebuyers use the Internet to search for new homes, encompassing more than 9% of households online  Or about six million visitors, to various real estate sites.  These users have accessed the real estate sites on an average of 1.8 days per month or a total of 13.9 minutes each day.  From 1996 to 2000, more than 400 business models were created across the entire real estate spectrum. ISQS 6347, Data & Text Mining 16

17. About IMW ISQS 6347, Data & Text Mining 17 Based in Austin, Texas, IMW (Internet Media Works!) is an ASP, specialized mainly in web-based application development, database integration, and web development and hosting for all kinds of businesses.Internet Media Works IMW has been more successful in selling its e-business services for commercial real estate. Its services include lead generation, real estate transaction management, property listing, realtor membership management, real estate indices, real estate auctions, etc., with COMMREX as a complete e- business solution.COMMREX IMW used to have up to 6 full-time employees and a few part- time employees.

18. ISQS 6347, Data & Text Mining 18 Website Hosting Services Core Membership Database Services Core Property Listing Database Services Optional Website Hosting Services Optional Membership Database Services Optional Property Listing Database Services Public User Application Services Networking and System Operation ServicesPublic User Support Internet Service Provider’s Services IMW’s Web-Based Application Services IMW’s Services

19. ISQS 6347, Data & Text Mining 19 Property ID Listor ID Address Property Type City                     Office Chapter Functions Specializations          Office           Company ID Address      Telephone # Company ID      Company Name Listor Name Chapter Feature Property Type Subtype 1      Type Name      Subtype 2 Subtype n M:1 M:M M:1 M:M Primary Key Secondary Key Link to a table Legends Property Listing Database Membership Database IMW’s Data Model