Re: Slow Vacuum was: vacuum output question

> On Tue, Jan 6, 2009 at 1:39 PM, Dan Armbrust
> <daniel(dot)armbrust(dot)list(at)gmail(dot)com> wrote:
>> Here is an interesting new datapoint.
>>
>> Modern Ubuntu distro - PostgreSQL 8.1. SATA drive. No Raid. Cannot
>> reproduce slow vacuum performance - vacuums take less than a second
>> for the whole database.
>>
>> Reinstall OS - Fedora Core 6 - PostgreSQL 8.1. Push data through
>> PostgreSQL for a couple hours (same as above) and now vacuum reports
>> this:
>
> Are you pushing the same amount of data through the ubuntu server? if
> not, then the comparison is invalid, if so, then yeah, there's some
> kind of difference between the platforms.
>
> Note that Fedora Core 6 is quite old compared to ubuntu 8.04 or 8.10.
> Also it's more likely to be installed on older and / or slower
> equipment.
>

Yep - actually, we pushed much more data through the Ubuntu system and
could never reproduce the problem. On the Fedora Core 6 system, the
problem happened very quickly.

In our testing here, the Ubuntu test was on the same hardware as the
fedora core 6 system (not just identical, but the same actual box)

It seems that there is some sort of bad interaction between some part
of the older OS and PostgreSQL. We have also seen what appears to be
the same issue on a Cent OS 4.4 system. Which is a rather similar
package level to Fedora Core 6.