Tuesday, 05 August 2008

We frequently get asked about Genome’s future in the light of Microsoft’s upcoming .NET 3.5 SP1 release, which includes the Entity Framework and related technologies such as LINQ and ADO.NET Data Services (see also the beta release announcement on Scott Guthrie's blog giving a broad overview about the new features).


LINQ (already released with .NET 3.5) provides query language capabilities for C# and VB.NET. Many new Microsoft technologies and products by other vendors rely on LINQ. It is crucial to integrate with it in order to stay connected with other technology trends. The distinction to LINQ2SQL needs to be emphasised, as many users confuse the two.
Genome has been fully integrated with LINQ since November 2007 (although we released several preview integration versions from 2006 on).  In fact, Genome was the first third party O/RM to provide LINQ integration. Developers who use Genome are thus not locked out of technology trends related to LINQ.


Astoria is the code name for Microsoft ADO.NET data services. It provides a REST interface for any data source that supports the interfaces IQueryable (introduced with LINQ) and IUpdateable (introduced with Astoria). It is not an O/RM, but rather a messaging layer over O/RMs or other data sources.
Astoria’s current release focuses on integrating with Entity Framework, but it appears that its extensibility is still unstable when it comes to other frameworks. Astoria is a great concept, but we doubt anyone is currently using it in production.
We are confident that Genome will support Astoria in the near future (before the end of this year), when integration possibilities have matured and the integration issues on Astoria’s side have been resolved. As with LINQ, developers who use Genome are not hindered from using this technology.

Entity Framework (EF)

Entity Framework actually consists of three major modules:

  • Entity Data Model (EDM): this is an abstraction of a relational model that introduces higher level concepts such as inheritance, composition and associations. Any database ER model can be mapped to an EDM. It also provides a neutral (i.e. vendor-neutral) dialect of SQL. Developers can map their databases to EDM and formulate queries to them in eSQL. EDM exposes “entities”, which are not CLR classes but rather structured data rows with meta data attached.
  • Provider Model: this is an extensibility point of Entity Framework for database vendors, to allow them to adapt eSQL and the EDM (data types, etc.) to vendor-specific database models (vendor SQL and database type systems).
  • LINQ To Entities: this is an object-relational mapping tool that allows CLR class models to be mapped to an EDM. In other words, it maps CLR classes to EF entities.

Genome actually overlaps with LINQ To Entities to a certain degree. Entity Framework itself is much more than an O/RM, as it represents the next level of abstraction for data access on the .NET platform (hence its original name, ADO.vNext). If Entity Framework proves to be useful and is widely adapted by our target customers, we can imagine integrating Genome with Entity Framework by replacing LINQ to Entities and allowing CLR business models to be mapped to EDMs with Genome. This would help our customers benefit from the Genome O/RM API and utilise EDM for other applications such as reporting, etc.

Our main concerns about Entity Framework and Genome’s value proposition:

Technical Overkill

There is the potential that the proposed development model and abstraction required by Entity Framework is overkill for certain applications (e.g. there are three models and all mappings between them need to be managed).

Tools provided by Entity Framework heavily depend on visual designers integrated in Visual Studio to manage the various mapping models and generate code from the models. This is especially the case with large and complex projects that involve large and complex models – which is what Entity Frameworks seems to target. We strongly doubt that relying on visual designers to that extent is a good approach. For example, resolving a merge conflict in the model (as can easily occur in projects with large teams) is not possible with a graphical designer, thus forcing developers to edit models manually.

Version 1 issues

Of course any first version of a product will have some immaturity issues which people usually have to more or less work around. However, since Entity Framework provides a radical and very complex new concept for abstracting data access, the functional completeness of Version 1 is very low compared to what the concept itself covers. The danger of encountering issues that are difficult or impossible to resolve is quite high in Version 1. This can be a particular problem in large enterprise projects, which is of course what Entity Framework appears to target.

The bottom line

The funny thing is that while LINQ2SQL is too simple for many applications, Entity Framework seems to be far too complex for many of our cases.

We are going to continue polishing Genome into an O/RM that we think is sophisticated enough to serve complex enterprise projects while also remaining simple enough to not force over-engineering. We are just about release Genome V4. Working on O/RM for .NET since 2002 has given us quite a lot of confidence in our approach: we balance flexibility and simplicity. We ensure that our customers are not locked out of technology trends on the .NET platform, so we will continue to integrate Genome with new technology concepts introduced by Microsoft in this field. We hope that our position as the first 3rd party O/RM to integrate with LINQ has already proven our commitment to this strategy.