Database Design

• Design is one of the most important aspects of this class.
• The author breaks this into three different types
  • Design from existing data (Ch 3-4)
  • Design for a new system (Ch 5-6)
  • Redesign of an existing system. (Ch 8)
• This includes
  • Proper tables/table structure
  • Relationships between tables
  • Proper constraints on data
• If you get it wrong
  • Queries may be overly complex
  • The database may be exceptionally slow.
  • You may lose data.
• But we know this, we have been designing programs!

What you need to learn

• I sort of don't like this section, but what the heck.
• It breaks the world into
  • Knowledge Worker - Someone who uses a db to produce reports, mine for data, ...
  • Programmer - Someone who builds applications that use the database
  • Database Administrator - Someone who designs, constructs and manages the database.
• This is nice, but Knowledge Workers should not be in the class.
• And programmers and DBAs should know what is going on.
• And if you are in a small company, you are likely to be all three.
• Look at the chart on P 20 - You need to read the entire book, cover to cover!

History of Databases

• Flat files, managed by the application.
• About '73, some commercial data base products were developed.
• '70. E. F. Codd published a paper on using relational algebra in databases.
• At first this was too theoretical for use, but now it dominates.
• Look at page 22, 7^th paragraph, "The 1977 ..."
• The 80s saw the rise of many relational databases.
• This includes products from Oracle and IBM
• Personal database systems were also on the rise.
• Microsoft charged in during the 90s and killed all of the personal DBMS.
• There have been attempts at building Object Oriented DBMS, but htis sems to have died out.
• The current push is driven by the internet
• XML is becoming a standard for information interchange.
• Some big data companies are using NoSQL databases. (Ch 12 if we get there)