我有一台性能出色的服务器，双6核3.3GHz 196GB内存，在4个10K SAS驱动器上具有RAID 10。我编写了一个脚本，该脚本应该下载每个北美文件，并逐个处理而不是一次处理整个文件。
processList.sh：
wget http://download.geofabrik.de/north-america/us/alabama-latest.osm.pbf -O ./geoFiles/north-america/us/alabama-latest.osm.pbf
osm2pgsql -d gis --create --slim -G --hstore --tag-transform-script ~/src/openstreetmap-carto/openstreetmap-carto.lua -C 2000 --number-processes 15 -S ~/src/openstreetmap-carto/openstreetmap-carto.style ./geoFiles/north-america/us/alabama-latest.osm.$
while read in;
do wget http://download.geofabrik.de/$in -O ./geoFiles/$in;
osm2pgsql -d gis --append --slim -G --hstore --tag-transform-script ~/src/openstreetmap-carto/openstreetmap-carto.lua -C 2000 --number-processes 15 -S ~/src/openstreetmap-carto/openstreetmap-carto.style ./geoFiles/$in;
done < maplist.txt
起初，它以接近40万个点/秒的速度开始处理，然后减慢到10k或更少
osm2pgsql version 0.96.0 (64 bit id space)
Using lua based tag processing pipeline with script /root/src/openstreetmap-carto/openstreetmap-carto.lua
Using projection SRS 3857 (Spherical Mercator)
Setting up table: planet_osm_point
Setting up table: planet_osm_line
Setting up table: planet_osm_polygon
Setting up table: planet_osm_roads
Allocating memory for dense node cache
Allocating dense node cache in one big chunk
Allocating memory for sparse node cache
Sharing dense sparse
Node-cache: cache=2000MB, maxblocks=32000*65536, allocation method=11
Mid: pgsql, cache=2000
Setting up table: planet_osm_nodes
Setting up table: planet_osm_ways
Setting up table: planet_osm_rels
Reading in file: ./geoFiles/north-america/us/alabama-latest.osm.pbf
Using PBF parser.
Processing: Node(5580k 10.7k/s) Way(0k 0.00k/s) Relation(0 0.00/s))
我将https://wiki.openstreetmap.org/wiki/Osm2pgsql/benchmarks中的性能内容应用于Postgresql：
shared_buffers = 14GB
work_mem = 1GB
maintenance_work_mem = 8GB
effective_io_concurrency = 500
max_worker_processes = 8
max_parallel_workers_per_gather = 2
max_parallel_workers = 8
checkpoint_timeout = 1h
max_wal_size = 5GB
min_wal_size = 1GB
checkpoint_completion_target = 0.9
random_page_cost = 1.1
min_parallel_table_scan_size = 8MB
min_parallel_index_scan_size = 512kB
effective_cache_size = 22GB
尽管起步良好，但在约20秒内迅速变质。知道为什么吗？我看了top，但并没有真正显示任何内容：
top - 22:48:46 up 3:11, 2 users, load average: 3.49, 4.03, 3.38
Tasks: 298 total, 1 running, 297 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 0.0 sy, 0.0 ni, 87.5 id, 12.5 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 19808144+total, 19237500+free, 780408 used, 4926040 buff/cache
KiB Swap: 29321212 total, 29321212 free, 0 used. 19437014+avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
16156 root 20 0 50.819g 75920 8440 S 0.7 0.0 0:02.81 osm2pgsql
16295 root 20 0 42076 4156 3264 R 0.3 0.0 0:00.27 top
1 root 20 0 37972 6024 4004 S 0.0 0.0 0:07.10 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.02 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:00.05 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
6 root 20 0 0 0 0 S 0.0 0.0 0:00.58 kworker/u64:0
8 root 20 0 0 0 0 S 0.0 0.0 0:01.79 rcu_sched
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
10 root rt 0 0 0 0 S 0.0 0.0 0:00.05 migration/0
11 root rt 0 0 0 0 S 0.0 0.0 0:00.03 watchdog/0
它的平均负载很大，使用时没有列出任何内容。以下是iotop
Total DISK READ : 0.00 B/s | Total DISK WRITE : 591.32 K/s
Actual DISK READ: 0.00 B/s | Actual DISK WRITE: 204.69 K/s
TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND
28638 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.60 % [kworker/u65:1]
20643 be/4 postgres 0.00 B/s 204.69 K/s 0.00 % 0.10 % postgres: wal writer process
20641 be/4 postgres 0.00 B/s 288.08 K/s 0.00 % 0.00 % postgres: checkpointer process
26923 be/4 postgres 0.00 B/s 98.55 K/s 0.00 % 0.00 % postgres: root gis [local] idle in transaction
1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % init
2 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kthreadd]
3 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/0]
5 be/0 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/0:0H]
6 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kworker/u64:0]
8 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_sched]
9 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [rcu_bh]
10 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [migration/0]
11 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/0]
12 rt/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [watchdog/1]