I can say Oracle database is a box of chocolates. You never know what you're gonna get. The more I learn about it, the more there is to learn. It's getting so much better with each new release too. See what Oracle 10g has to give us.. recycle bin, flashback queries, regular expressions ... to name a few. It's intriguing and interesting. Many people found my previous hub on PL/SQL very useful. This hub additionally has questions in SQL along with PL/SQL. Some of these are job interview questions while some others are just interesting information ( which of course could be asked in interviews too ), if you want to be an Oracle developer. The answers that I provided are only for reference and are open to correction.