Hi Emma,
The survey was answered by about 10 institutions but I don't know which ones are using postgresql or oracle.
I think that the less bugs idea is what everyone would want for the toolkit and might not be necessarily according to the bugs found and fixed in their installations, besides I'd say that not everybody is used to contribute their code (even though it would be the best for the community as you said), it takes some time to contribute code, anyway we need to motivate people to contribute their fixes or at least report about the errors found.
