DataObjects.Net vs NHibernate: conceptual differences and feature-based comparison

I written the document that might help the people choosing among DataObjects.Net and NHibernate to make a decision. Currently its second part related to feature-based comparison (feature matrix) is actually a preliminary one (that's explained in the document), so later I'll rewrite it. But anyway, I hope this will be helpful.

As usual, any comments and suggestions are welcome.

Preliminary document: ORM feature matrix

I'd like to share an early link to feature-based ORM comparison we're working on: "The Most Comprehensive Feature-Based Object-Relational Mapping Tool Comparison Ever :)™"

The document is incomplete yet:

• some cells are empty - i.e. their content is currently unknown;
• there can be some mistakes (it wasn't checked by community yet);
• as you might suspect, a copy of this document is edited by ORMBattle.net participants, so its version including most of the tools tested there must also appear soon. It won't appear "as-is" at our own web site, but we'll use ~ the same columns from it (direct comparison with commercial competitors in marketing materials is normally not acceptable).

On the other hand, the feature map is already quite comprehensive: there are about 270 features organized into hierarchical structure. It is far more detailed then any other ORM comparison we were able to find (likely, this one is the most detailed, but really ancient predecessor).

Likely, the document is currently a bit biased toward DataObjects.Net from the point of selected features, but I feel this will be "automatically fixed" by the community shortly: vendors are allowed to add any non-duplicating features and sections there, as well as propose to exclude the non-important ones.

On the other hand, it's clearly much less biased document as e.g. this one (although I understand it doesn't pretend to be a real comparison). I.e. it can be hardly called as promotional material.

Our final goal is to develop a feature map including major ORM tools and features that are mutually agreed by various ORM vendors, where each vendor is responsible for contents of his own column (i.e. cheating is possible, but I suspect users & competitors won't accept this well); the table you see is our initial investment into this process.

Availability of such comparison should help developers to choose the tools they need based on their own requirements, as well as understand the relationships between features better (hierarchy seems really helpful here - I already got few quite positive comments related to the structure of the document).

An accompanying document commenting each section there and describing DataObjects.Net advantages / disadvantages in comparison to other tools should also appear soon.

Don't forget to study the comments at the bottom of the first sheet, as well as "Remarks" sheet.

LINQ query translation optimization - one of real-life cases we've faced

Take a look at the issue 761.

It took about 2 hours to implement such transformation with SQL DOM - the changes Alexis Kochetov has made to resolve this issue are really tiny. It's difficult to imagine how ORM tools without SQL DOM-like model (e.g. NHibernate) can handle such cases. So our approach is quite solid from this point.

P.S. Tobias, thank you a lot for your analysis of this case!

// This post is actually written solely to advertise our support services and the team itself ;)

Honest comparison of NH and EF?

I just published a post about Fabio Maula's comparison of NHibernate and Entity Framework. I think it deserves to be re-posted here.

If you don't know the story, Oren Eini (Ayende @ Rahien) and Fabio Maula, likely, are the most well-known criticizers of ORMBattle.NET. As well as the most known NHibernate developers.

Preliminary ORM performance comparison: DataObjects.Net 4 vs NHibernate

We've just adopted our CrudTest for NHibernate. First results:

DO4 (LINQ):
Insert: 28,617 K/s.
Update: 34,111 K/s.
Fetch & GetField: 8,682 K/s.
Query: 1,486 K/s.
CachedQuery: 8,176 K/s.
Materialize: 358,671 K/s.
Remove: 41,108 K/s.

NHibernate (LINQ):
Insert: 12,936 K/s.
Update: 12,939 K/s.
Fetch & GetField: 7,152 K/s.
Query: 95,7/s.
CachedQuery: Cached queries are not supported in NH yet.
Materialize: 37,892 K/s.
Remove: 13,012 K/s

The highlighted numbers show ~ 10 times difference, although DO wins in all other cases as well. Results of this test for several other ORMs are upcoming, the project will be shared @ Google Code.

In addition, we're developing general LINQ test as well. For now LINQ for NHibernate passes ~ 25 tests out of 100. This mean only very basic LINQ stuff really works on this release. DO4 passes ~ 98 tests there (it still misses passing arrays/collections as query parameters).

P.S. The optimization we've made during last 2 weeks is already quite successful (although we still work on materialization performance). Pre-optimization results can be found here.