A copy-and-patch JIT in Rust compiles in about 5 microseconds

Sources: malisper write-up, HN discussion
Summary: The post describes a copy-and-patch JIT written in Rust that compiles code in about 5 microseconds. The author applies it in pgrust to JIT compile every SQL query rather than a subset, and names LLVM and generated C as the alternatives whose compile times rule that out.
Why it matters: Compile time rather than generated-code quality is what has kept database JIT compilation to a subset of queries, so a 5 microsecond compile changes which queries are eligible at all.