Benchmarking Postgres 17 vs 18

This post benchmarks Postgres 17 against Postgres 18, specifically evaluating the performance impact of the new `io_method` settings (`sync`, `worker`, `io_uring`) on read-only workloads. It details extensive benchmark configurations using sysbench on various AWS EC2 instances with different storage types (gp3, io2, local NVMe) and IOPS/throughput settings. The analysis compares query-per-second (QPS) results for single and high concurrency scenarios, demonstrating how storage latency and IOPS, as well as workload characteristics (range size, concurrency), influence the performance of each `io_method`. It concludes that `io_method=worker` is a strong default, local NVMe storage offers superior price-performance, and `io_uring`'s benefits are workload-dependent.