Melanie Plageman ff79b5b2ab Increase default effective_io_concurrency to 16 ... The default effective_io_concurrency has been 1 since it was introduced in b7b8f0b609. Referencing the associated discussion [1], it seems 1 was chosen as a conservative value that seemed unlikely to cause regressions. Experimentation on high latency cloud storage as well as fast, local nvme storage (see Discussion link) shows that even slightly higher values improve query timings substantially. 1 actually performs worse than 0 [2]. With effective_io_concurrency 1, we are not prefetching enough to avoid I/O stalls, but we are issuing extra syscalls. The new default is 16, which should be more appropriate for common hardware while still avoiding flooding low IOPs devices with I/O requests. [1] https://www.postgresql.org/message-id/flat/FDDBA24E-FF4D-4654-BA75-692B3BA71B97%40enterprisedb.com [2] https://www.postgresql.org/message-id/CAAKRu_Zv08Cic%3DqdCfzrQabpEXGrd9Z9UOW5svEVkCM6%3DFXA9g%40mail.gmail.com Reviewed-by: Andres Freund <andres@anarazel.de> Discussion: https://postgr.es/m/CAAKRu_Z%2BJa-mwXebOoOERMMUMvJeRhzTjad4dSThxG0JLXESxw%40mail.gmail.com		2025-03-12 15:57:44 -04:00
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src	Increase default effective_io_concurrency to 16	2025-03-12 15:57:44 -04:00
KNOWN_BUGS
Makefile	Remove distprep	2023-11-06 15:18:04 +01:00
MISSING_FEATURES
TODO