Even the performance benefits are not big enough compare to the GIL. Biggest problem of the process model might be the cost of having too many DB connections.

Even the performance benefits are not big enough compare to the GIL. Biggest problem of the process model might be the cost of having too many DB connections. Each client need a dedicated server process. Memory usage and the context switching overhead. Or if there is no connection pool, connection time overhead is very high. This problem has been well addressed with a connection pool. Or having a middle ware instead of exposing the DB directly. That works very well so far. Oracle has been supporting the thread based model and it's been usable for decades. I remember I tried the thread based configuration option (MTS or shared server) in 1990s. But no one likes that at least within my Oracle DBA network. It would be a great research project but it would be a big problem if the community pushs this too early.