Abhishek Sur, the Client App Development MVP from Kolkata, India, has authored a series of posts on his blog delving deep into internals of C# ad ADO.NET.
Check out these very useful posts, and share them with your communities.
ADO .NET internals: Part 1 | Part 2
What does deep dive means? Is it related to origin and enhancement of language in past?
'Deep dive' actually is a little abstract... it can refer to a deeper look at the language/technology from any perspective than just the language specifics and syntax.