pgrust reimplements PostgreSQL in Rust and passes the regression suite

Category: Languages
Status: discussion
Sources: pgrust repository, HN discussion
Summary: pgrust (by GitHub user malisper) is a from-scratch reimplementation of PostgreSQL in Rust targeting compatibility with Postgres 18.3. The README states it passes 100% of the Postgres regression suite (more than 46,000 regression queries), is disk-compatible with existing Postgres 18.3 data directories, and can boot from an existing installation. The README also states it is not production-ready and not performance-optimized, that PL/Python, PL/Perl, and PL/Tcl are not generally compatible yet, and that the project used AI-assisted programming for deeper server changes. License is AGPL-3.0.
Comments: HN commenters draw a line between a rewrite and an AI-assisted rewrite, and argue that a database earns reliability from production exposure rather than passing the test suite. Several question the AGPL-3.0 choice for a Postgres-compatible server.
Why it matters: It extends the memory-safe-rewrite pattern (after the Bun Zig-to-Rust port) into database internals and tests how much a passing regression suite proves about a system whose value is durability.
Follow-up: Watch for performance numbers, extension compatibility progress, and whether the project reaches a production-usable milestone.