I have a hard time believing PostgreSQL performance is better than Oracle, can you give an example? How big is your database and how much did migrating cost you?
Yep, it's surprising how much performance you can get when you're not paying Oracle millions for licensing.
A lot of people who think Oracle is amazingly fast, think so because who puts a million dollar DB on thousand dollar hardware? Put any major DB on equivalent hardware and you'll get some pretty damn good performance.
Nobody has any data they can show you, because Oracle's EULA prohibits both running their software and sharing that data, you can only do one of those.
My experience is that Postgres has better performance than Oracle on much smaller machines. If you have very simple data, with very simple joins, and never deviate from the trivial "select columns from table join table using (foreign key)" you may have a different experience, because Oracle is just great on those.
have you tried both? the oracle eula prevents disclosing performance stats. pg allows user defined indexes to be added to kernel and integrated with optimizer, creating some pretty sophisticated optimization techniques. we have the text search index easily handling 20mil+ pdfs with the rum index from postgrespro http://github.com/postgrespro/rum.
Have you seen the pricing for Exadata racks? I ran the numbers a few months back and over 5 years, Oracle was 4x as expensive for my workloads. It's also easier to find AWS people than Oracle people.
