I spent 6 years at Oracle and did a fair amount of performance tuning. In general, it is not the DBA's job to tune SQL for the applications. Most DBA's have only a vague understanding of those issues. Their job is generally to keep the database running reliably.
Also, relying on a package such as hibernate to do your tuning only proves that your SQL will remain untuned.
Tuning involves examining the use pattern for the application, examining the storage pattern for the underlying database, and choosing among SQL statements based on the patterns of data access you discover. There is a reason why Database experts are well paid.

The one thing you have to remember is that open source leads to new things and concepts. Just ask Astrum Inc. http://www.astruminc.com what astrum did was to develop the first SUSE based Solution Stack using Novell technology. What they produced and what the independent testing reported was a beast of an appliance and Astrum published the reports on it's website was the first ever Identity based encryption system that can target users who have access to critical data or compliant data and harden policies that are compliance mandated. Lock them down in the appliance and integrate nCipher HSM Encryption Card into eDirectory then developed a key management system that never exposes any part of the key. Now according to nCipher as told to me at RSA this makes the Astrum solution the only solution to meet the up coming FIPS 3 compliance changes and make this appliance very unique in the market space.
The problem:
The concept was presented to Novell under NDA two years ago in 2006 and promises where made protection agreements signed and software groups were worked with to ensure no competitive issues may arise. They did not! So Astrum shared with Novell executives the plan that at the end of the day would map 8 of the PCI requirements to the appliance and all Novell products could sit on top. What happened is Astrum became the first ever to develop and Novell based solution stack using SUSE enterprise in a appliance only to have it stolen from them!.. Hence the following links.
http://sev.prnewswire.com/computer-electronics/20080416/AQW05816042008-1...
http://www.novell.com/linux2/appliance/
So if the solution is so new why expose a concept to a company who will steal it if it has enough market impact and when the solution has ability to change a business direction for a major software company like Astrum did for Novell. Prior to 07 from what I understand Novell couldn't spell compliance much less understand an appliance?
Develop for Novell on SUSE or jeOS, NO WAY!!!

The one thing you have to remember is that open source leads to new things and concepts. Just ask Astrum Inc. http://www.astruminc.com what astrum did was to develop the first SUSE based Solution Stack using Novell technology. What they produced and what the independent testing reported was a beast of an appliance and Astrum published the reports on it's website was the first ever Identity based encryption system that can target users who have access to critical data or compliant data and harden policies that are compliance mandated and lock them down in the appliance and integrate a eDirectory based HSM encryption card and develop a key management system that never exposes any part of the key. Hence this makes it the only solution to meet the up coming FIPS 3 compliance changes and make this appliance very unique in the market space.
The problem:
The concept was presented to Novell under NDA two years ago in 2006 and promises where made protection agreements signed and software groups worked with to ensure no competitive issues may arise. They did not! So Astrum shared with Novell executives the plan that at the end of the day would map 8 of the PCI requirements to the appliance and all Novell products could sit on top. What happened is Astrum became the first ever to develop and Novell based solution stack using SUSE enterprise in a appliance only to have it stolen from them!.. Hence the following links.
http://sev.prnewswire.com/computer-electronics/20080416/AQW05816042008-1...
http://www.novell.com/linux2/appliance/
Hence, who would expose there concept to a company who will steal it if it has enough market impact and that has ability to change a business direction for a major software company like Astrum did for Novell. Prior to 07 Novell couldn't spell compliance much less understand an appliance?
Develop for Novell on SUSE or jeOS, NO WAY!!!