autovacuum_work_mem
No restart — takes effect on reloadmemory per autovacuum worker (MB)
Memory each autovacuum worker may use (defaults to maintenance_work_mem).
What it does
autovacuum_work_mem is the per-worker memory budget for autovacuum's dead-tuple tracking. It defaults to -1, meaning 'use maintenance_work_mem' — which matters because several autovacuum workers can run at once.
How to tune it
Set an explicit value when you want a large maintenance_work_mem for interactive index builds without letting autovacuum_max_workers × that value blow up memory. For example maintenance_work_mem = 2GB but autovacuum_work_mem = 256MB.