There have been a quite good discussions regarding Oracle and MySQL in [ this ] particular Slashdot post.
Clearly, in terms of high-end features, MySQL is FAR from matching Oracle.
Example, this is the shortest paragraph that quite nicely explains what Oracle really is. It’s just too mind-boggingly different.
Howeever, MySQL is more popular due to being available for free and good enough for most people. Which I have no problem with, in fact I’m using MySQL myself.
If you’re interested in more comparisons, then click here.
A note on database portability (since I was involved heavily on this topic for months) – even though this poster said that moving from Oracle is the hardest, in reality, I suspect that pretty much all database migration is painful. I’ve migrated a few apps which uses MySQL to Oracle, one of them actually already used ADODB – yet there were still problems that made me pull my hair.
MySQL broke quite a few ANSI-SQL standards – although to be fair, I imagine that Oracle extended quite a lot of them instead; so that if you have apps optimized for Oracle, then you’ll experience hell if you want to migrate it.
Back to the topic – the right way to compare Oracle / MySQL / whatever is not just strictly from performance / feature-set. If you do it this way, be prepared to be nastily surprised.
For example, the potential problem of going with Oracle are quite a lot as well.
First, you may encounter problems with its complex licensing scheme. Second, you need a highly skilled Oracle DBA specialist to be able to fully utilise it – jack-of-all-trade like me just won’t cut it. Third, if you think Oracle is expensive, the support cost may deter you from actually purchasing it (not buying support contract is plain suicide). Etc.
If those still doesn’t stop you from buying Oracle, then here’s a tip to make it easier on your budget.
In the end, the right way to compare (database) software is by comparing it against your own criterias / needs / requirements. Any other way, and you may be disappointed later in the future.