Re: VACUUM degrades performance significantly. Database - Mailing list pgsql-general

Stephen wrote:
> Nope, I installed the RedHat 9 myself and no one else has access to this
> machine. It's either that Redhat uses a different elevator setting for SCSI
> drives than IDEs or the latest Redhat updates I applied brought it to my
> current numbers. Besides, I believe your values may indicate an outdated
> system because IIRC the max_bomb_segments has been disabled and should
> always be zero because of some inefficiencies in the elevator algorithm.
>
> Regards, Stephen

Well, I obtains the same values for two different RH9 installation:

# uname -a
Linux XXXX 2.4.20-13.9smp #1 SMP Mon May 12 10:48:05 EDT 2003 i686 i686
i386 GNU/Linux
# elvtune /dev/hda6

/dev/hda6 elevator ID           1
         read_latency:           64
         write_latency:          8192
         max_bomb_segments:      6


# uname -a
Linux XXXX 2.4.20-20.9smp #1 SMP Mon Aug 18 11:32:15 EDT 2003 i686 i686
i386 GNU/Linux
# elvtune /dev/sda7

/dev/sda7 elevator ID           5
         read_latency:           64
         write_latency:          8192
         max_bomb_segments:      6


I'll try on my laptop.



Reagards
Gaetano Mendola