Note: #28505 to allow interception of the LINQ expression tree has been split off from this and implemented in EF7.

Use cases

• Generating DB commands for operations not currently supported by EF (e.g. ExecuteUpdate/Delete (AKA bulk update, without loading data into memory) #795)
• Extending with provider-specific LINQ operators (like how linq2db allows a wide variety of SQL constructs)
• More flexible and robust query filters
• Query validation and transformation

The current query generation pipeline is hard to extend without relying on implementation details.

Proposal

Enable intercepting the translation steps in QueryCompilationContext.CreateQueryExecutor.
API details are to be discussed here, I don't have a concrete proposal yet.