In this benchmark ObjectDB is far the fastest DB: http://www.jpab.org/All/All/All.html
But I cannot see any other benchmark results from ObjectDB. Is anyone using ObjectDB? Is it production ready? What are the experiences?
I've used it for a number of projects and products, both professionally and personally. I've used it for a little over 5 years now. These are my experiences of it:
Disclaimer: I own a server license and an OEM license, and over the years have got to know the creator(s). I have no other commercial relationship with the ObjectDB company - in other words, I gain nothing commercially if they sell more copies. I just like the product.
My usages:
personally: I used it as part of a commercial product that came out of my phd, to persist UML2/EMF models. these are complex things with many, many classes and ObjectDB was the only product i was able to find that could handle the complex linking with adequate performance. it has been a stellar performer in this environment.
work related: I work in an investment bank and we used ObjectDB to persist the workflow states and handle persistence in a large grid (>2000 nodes) environment. It worked very well in this environment as well.
I was also a consultant to Gentleware at one point back in 2007 or so, and we evaluated ObjectDB against db4o, hibernate etc. It outperformed any competition by close to an order of magnitude. This was my first commercial experience with it.
So, the bottom line is that I have found ObjectDB to be extremely fast, and rock solid. We tested it up to 10GB alone on the UML2 models and there were no problems there. I've never had a database die on me or get corrupted in all my time of using it. Furthermore, its footprint is pretty small. In short, it's a bit of an unsung hero in the space.
My experiences concur with the jpab benchmarks - they make uncomfortable reading for the owners of other products, but... perhaps i'm not completely unbiased in this though - i've had much contact with the creator(s) of ObjectDB over the years and pushed them to release the benchmarks. in particular, i felt they should make the graph linear rather than logarithmic - it shows the performance of ObjectDB is vastly better in most cases.
As an aside, the reason why you won't find many other benchmarks on this or any other JPA product is that none of the vendors can generally agree on a benchmark and tend to accuse others of bias. I've seen this first hand many times. Some people prefer polepos, but this is dominated by db4o and those people won't release the dn results for instance. Some database vendors won't allow results etc. It's a minefield and the creators of ObjectDB are no different here. Everyone likes to control their own benchmark ;-)
anyway, to cut a long story short, my honest experience is that ObjectDB is very quick, production ready (for a number of years back to 1.x) and well supported. It's a very good product.