Complex Queries

[tsutomi]

I apologize for using this method for writing to you a request of information, but unfortunately I found no other reference.
I'm developing a project named DeveelDB, a SQL-99 database system for .NET: I recently rebooted the whole project, that was quite old indeed, but not well-written.
In this perspective I'm writing, among others, a LINQ interface to it and I'm pondering which option to follow:

• Write my own provider
• Use IQToolkit
• Use Re-Linq toolkit

I explored the source code of IQToolkit and Re-Linq and I must say that your code looks quite clean and straight forward when compared to Re-Linq.
On the other side, Re-Linq seems to be used in real world business cases (NHibernate and EF7 above all), while IQToolkit seems ignored.

I wish to know what is the confidence you have on complex queries and mappings (eg. joins, projections, sub-queries, etc)? What is the code coverage?

When I see the projects for SQL Server, MySQL and other examples, I think it would be very simple to start writing my provider following those examples, but I also want to provide a professional project to be used (thing that I haven't done for years) in complex and challenging contexts.

Thank you for all your time.