Hi! A few days ago I read the article about PostgresML migration from Python to Rust. I was especially interested in your performance results since I have an additional idea of how it's possible to potentially improve the PostgresML performance.

Recently I checked Profile-Guided Optimization (PGO) improvements on multiple projects - the results are available here. According to the tests, PGO helps with achieving better performance in many software applications like databases, compilers, network applications, etc. I think trying to optimize PostgresML with PGO can be a good idea.

I can suggest the following action points:

• Perform PGO benchmarks on PostgresML. If it shows improvements - add a note to the documentation about possible improvements in PostgresML's performance with PGO. PGO documentation examples in different projects you can find here.
• Providing an easier way (e.g. via a build option) to build PostgresML with PGO can be helpful for the end-users and maintainers since they will be able to optimize PostgresML according to their own workloads.
• Optimize pre-built PostgresML binaries with PGO.

Testing Post-Link Optimization techniques (like LLVM BOLT) would be interesting too (Clang and Rustc already use BOLT as an addition to PGO) but I recommend starting from the usual PGO.

For the Rust projects, I recommend starting with cargo-pgo. More details about PGO support in Rust can be found in the official docs.

Here are some examples of how PGO optimization is integrated in other projects:

• Rustc: a CI script for the multi-stage build
• GCC:
  • Official docs, section "Building with profile feedback" (even AutoFDO build is supported)
  • A part in a "wonderful" configure script
• Clang: Docs
• Python:
  • CPython: README
  • Pyston: README
• Go: Bash script
• V8: Bazel flag
• ChakraCore: Scripts
• Chromium: Script
• Firefox: Docs
  • Thunderbird has PGO support too
• PHP - Makefile command and old Centminmod scripts
• MySQL: CMake script
• YugabyteDB: GitHub commit
• FoundationDB: Script
• Zstd: Makefile
• Foot: Scripts
• Windows Terminal: GitHub PR
• Pydantic-core: GitHub PR
• file.d: GitHub PR
• OceanBase: CMake flag
• NodeJS: Configure script