That is significantly dependent on the software architecture. MariaDB's design is not particularly modern (not a knock against MariaDB, it is an older system) and employs none of the software architecture required for high-scale and high-performance kernels that, as a side-effect, makes it difficult to accidentally create the conditions for a segfault regardless of the language. The design motivation is actually optimal dynamic resource scheduling under heavy unpredictable workloads, not memory safety. Rust's borrow checker doesn't work with these memory models, so you'll be in the same boat as C++ regardless.

I always found it theoretically interesting that schedule-based safety architectures, which are focused more on optimal resource allocation than safety per se (its all about extreme throughput traditionally), asymptotically converge on memory safety too as a practical matter for the same reason they also require almost no locking. By doing the safety analysis (many kinds, not just memory) at runtime, tiny dynamic modifications to the execution schedule are sufficient to provably (using TLA+ and similar) avoid many types of "unsafety" without the design compromises required to enable some of this analysis at compile-time. It requires a non-traditional software architecture, and it doesn't play nicely with a lot of existing code, due to the level of execution control required but I see more and more systems being designed this way at the high-end of the data infrastructure market.