Đang tải bảng tin…
Lobsters0 Hot0 bình luận12 phút đọc
kernel asynchronous reads in PostgreSQL 19 (io_uring)
PostgreSQL 19 introduces io_uring as an io_method option, enabling kernel-managed asynchronous buffered I/O. Unlike the worker method (which uses dedicated IO worker processes issuing synchronous pread64/preadv calls), io_uring submits read requests directly to the kernel's submission queue and retrieves completions from the completion queue, allowing multiple reads to be in-flight simultaneously. The post demonstrates this via strace output showing io_uring_enter syscalls, EXPLAIN ANALYZE output with prefetch and I/O statistics, and top output comparing process states. Key insight: io_combine (combining nearby block reads) works independently of io_method. With io_uring and many parallel workers, load average can spike above 25 while CPUs remain nearly idle — a monitoring challenge for sysadmins. The approach hides I/O latency through prefetching and deep request pipelines for predictable access patterns like Sequential Scan and Bitmap Heap Scan.
Nguồn: https://dev.to/franckpachot/iouring-buffered-reads-in-postgresql-19-iouring-mcn. 8sync News chỉ tóm tắt và dẫn link; bản quyền nội dung thuộc tác giả và nguồn gốc.
Đề xuất cho bạn
All Things Open29 Hot3 phútAI
What is immutable Linux and should you switch to it?
Hệ điều hành Linux bất biến (Immutable Linux) phân phối OS dưới dạng image phiên bản có …
