postgresql-performance using sysbench

Claus Guttesen kometen at
Fri Feb 1 00:24:16 PST 2008

> Just a thought on the effect that HZ has on filesystem (and overall)
> performance :
> Linux has sort of backtracked from defaulting to HZ=1000 and enable it
> only on kernels compiled
> for "Desktop" work, and setting HZ=250 for the "Server" profile.

I'm doing some db-imports on postgresql on a file which takes 3 hours
and 40 min. with default HZ (1000). Then I changed HZ to 250 (in
loader.conf) and rebooted. The import still took 3 h. 40 min. so
altering HZ does not seem to have any influence.

#>sysctl kern.clockrate
kern.clockrate: { hz = 250, tick = 4000, profhz = 166, stathz = 33 }


When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.


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