maintenance_io_concurrency
No restart — settable per sessiontuned by pgconfiguratorPostgreSQL 13+count (concurrent I/O requests)
Concurrent I/O for maintenance work like VACUUM prefetch.
What pgconfigurator would set
32 GB · 8 vCPU · NVMe · OLTP
Computing…
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What it does
The maintenance counterpart to effective_io_concurrency: it sets how many I/O requests maintenance operations (notably VACUUM) may issue at once for prefetching, so they read ahead efficiently on storage that handles parallel I/O.
How to tune it
On SSD/NVMe the default (16 in current PostgreSQL) is a reasonable amount of read-ahead for maintenance — keep it or raise it to speed VACUUM on storage that handles parallel I/O; set 0 for a single spinning disk.