PostgreSQL 18 Beta: Asynchronous I/O Revolutionizes Performance

PostgreSQL 18 Beta 1 introduces highly anticipated asynchronous I/O (AIO), marking a significant leap in I/O handling. AIO dramatically improves performance, especially in cloud environments with high latency, by allowing the database to issue multiple read requests concurrently. Currently limited to reads (writes may be added later), AIO utilizes a new `io_method` configuration parameter offering synchronous, I/O worker, and `io_uring` modes. `io_uring`, on compatible Linux kernels, delivers the best performance. Benchmarks on AWS show 2-3x read performance improvements for read-heavy workloads. However, AIO changes performance monitoring; `EXPLAIN ANALYZE` I/O timing may be less precise, requiring the new `pg_aios` view for detailed analysis.