[fschuett]

In the short term, you wouldn't want to run databases in WASM. You could, but it's not really worth the effort, as long as the WASM runtime allows TCP connections, you can just connect to any hosted DB as usual.

For performance, we ship three compiler backends: LLVM (fast execution, but slowest compilation), cranelift and singlepass (our own compiler, very fast compilation and you can compile untrusted code - but slowest execution). There is a slowdown, but the goal is to keep that at a minimum (proper performance tracking is on the bucket list). We are pre-compiling the python.wasm (which was already pre-optimized when the compilation to WASM happened) with LLVM, so you should get assembly that is very close to the native execution, with the exception of the necessary VM overhead. The goal is to make it so that the interoperability gains are worth the performance hit.