Minimize checkpointer and walwriter io during pg_restore

[Ron Johnson <ronljohnsonjr@xxxxxxxxx>]

PG 14.12

Currently, when doing a pg_restore with 24 threads, I see this when using iotop:

checkpointer 90+ MB/s
walwriter 45+ MB/s

Is there any way to minimize it more than I already have, or is that just how much work needs to be done when restoring the database?

Here's the current configuration (which will be reset after the post-restore ANALYZE):

declare -gi SharedBuffs=32
declare -gi MaintMem=3 # so the oom killer doesn't kill it
declare -gi CheckPoint=30
declare -gi MaxWalSize=36
declare -gi WalBuffs=64
pg_ctl restart -wt$TimeOut -mfast \
        -o "-c hba_file=$PGDATA/pg_hba_maintmode.conf" \
        -o "-c fsync=off" \
        -o "-c log_statement=none" \
        -o "-c log_temp_files=100kB" \
        -o "-c log_checkpoints=on" \
        -o "-c log_min_duration_statement=120000" \
        -o "-c shared_buffers=${SharedBuffs}GB" \
        -o "-c maintenance_work_mem=${MaintMem}GB" \
        -o "-c synchronous_commit=off" \
        -o "-c archive_mode=off" \
        -o "-c full_page_writes=off" \
        -o "-c checkpoint_timeout=${CheckPoint}min" \
        -o "-c max_wal_size=${MaxWalSize}GB" \
        -o "-c wal_level=minimal" \
        -o "-c max_wal_senders=0" \
        -o "-c wal_buffers=${WalBuffs}MB" \
        -o "-c autovacuum=off"