Memory-mapped file IList implementation, for storing large datasets “in memory”?

Question

I need to perform operations chronologically on huge time series implemented as IList. The data is ultimately stored into a database, but it would not make sense to submit tens of millions of queries to the database.

Currently the in-memory IList triggers an OutOfMemory exception when trying to store more than 8 million (small) objects, though I would need to deal with tens of millions.

After some research, it looks like the best way to do it would be to store data on disk and access it through an IList wrapper.

Memory-mapped files (introduced in .NET 4.0) seem the right interface to use, but I wonder what is the best way to write a class that should implement IList (for easy access) and internally deal with a memory-mapped file.

I am also curious to hear if you know about other ways ! I thought for example of an IList wrapper using data from db4o (someone mentionned here using a memory-mapped file as the IoAdapterFile, though using db4o probably adds a performance cost vs. dealing directly with the memory-mapped file).

I have come across this question asked in 2009, but it did not yield useful answers or serious ideas.