I get very different (contradictory) behavior. Server with fast RAID,
32GB
RAM, 2 x 4 core 3.16Ghz Xeon 54xx CPUs. CentOS 5.2
8.3.6
That's a very different serup from my (much less powerful) box, so that
would explain it...
No disk wait time during any test. One test beforehand was used to prime
the disk cache.
100% CPU in the below means one core fully used. 800% means the system
is
fully loaded.
pg_dump > file (on a subset of the DB with lots of tables with small
tuples)
6m 27s, 4.9GB; 12.9MB/sec
50% CPU in postgres, 50% CPU in pg_dump
If there is no disk wait time, then why do you get 50/50 and not 100/100
or at least 1 core maxed out ? That's interesting...
COPY annonces TO '/dev/null';
COPY 413526
Temps : 13871,093 ms
\copy annonces to '/dev/null'
Temps : 14037,946 ms
time pg_dump -Fc -t annonces -U annonces --compress=0 annonces >/dev/null
real 0m14.596s
user 0m0.700s
sys 0m0.372s
In all 3 cases postgres maxes out one core (I've repeated the test until
all data was cached, so there is no disk access at all in vmstat).
Size of dump is 312MB.
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