It's for sure the question that a lot of people have. Initially we had more details about that in the blog post, but we didn't want it to become a "Zig vs Rust" blog post, so we kept it to a minimum.
I will expand just a little bit more here:
First, I think the fact that Rust can be a trusted language for Postgres is a huge advantage, and I am excited about it! I hope we will have the chance to use it and contribute to pgrx as well.
Postgres is not only written in C, but it has developed its own particular style of C code. For example: arena memory allocator (memory contexts), exceptions via setjmp/longjmp (ereport), single-threaded communicating via shared memory, SPI for accessing the data via SQL, etc. Some of these mechanisms kind of conflict with the way Rust likes to do things.
Because of the above, pgrx has to do harder work to expose functionality. It's possible, just a lot of work. In Zig, we can use pretty much anything directly or with small wrappers.
If you need to call into C a lot, you need to use unsafe, and that negates some of the memory safety advantages of Rust. Also, Rust unsafe code is harder to write.
I will expand just a little bit more here:
First, I think the fact that Rust can be a trusted language for Postgres is a huge advantage, and I am excited about it! I hope we will have the chance to use it and contribute to pgrx as well.
Postgres is not only written in C, but it has developed its own particular style of C code. For example: arena memory allocator (memory contexts), exceptions via setjmp/longjmp (ereport), single-threaded communicating via shared memory, SPI for accessing the data via SQL, etc. Some of these mechanisms kind of conflict with the way Rust likes to do things.
Because of the above, pgrx has to do harder work to expose functionality. It's possible, just a lot of work. In Zig, we can use pretty much anything directly or with small wrappers.
If you need to call into C a lot, you need to use unsafe, and that negates some of the memory safety advantages of Rust. Also, Rust unsafe code is harder to write.