How should we design a database? You decide! скачать в хорошем качестве

How should we design a database? You decide!

When creating database tables there are lots of decisions you need to make. For example, should you use: Surrogate or natural primary keys? Check constraints or lookup tables for status codes? Store or calculate derived values? Each choice affects the table structure and the queries you'll write to fetch data. Watch this interactive session to see how these decisions affect your schema. See which options the audience voted for and hear the trade-offs discussion. Watch how the winning choices affect the schema and queries against. Highlights include: 01:50 - The challenge design the schema for an international sporting league 05:00 - Surrogate or natural (ISO codes) keys for the countries tables? 09:25 - Use a check constraint or lookup table to restrict game statuses? 12:30 - Store the start times in UTC or a timestamp with time zone using the time zone for the home country 17:35 - Store the home/away teams in each game as columns or rows? 22:40 - For unplayed games, should the score for each team be null or not null with a default of zero? 29:30 - Store or calculate the win/draw/loss points for each team for completed games? 34:10 - Demo building the schema based on the audience votes for each question 39:05 - Query to find all the games for a country with results for completed games 44:15 - Show the fixtures in the next seven days 47:10 - Query to display the league 51:00 - Summary of pros and cons for each decision 58:30 - Consider the tradeoffs Final script for demo https://livesql.oracle.com/apex/lives... Final script with opposite choices https://livesql.oracle.com/apex/lives... Learn SQL for free http://bit.ly/learn-sql-free-dfd-f