Re: strange 'vacuum verbose analyze' behaviour

On Fri, 28 Jan 2005, Oleg Bartunov wrote:

> On Thu, 27 Jan 2005, Tom Lane wrote:
>
>> Oleg Bartunov <oleg(at)sai(dot)msu(dot)su> writes:
>>> Day ago we run 'vacuum verbose analyze;' and now we're observing
>>> strange output (see below). We see many repeated passes through the
>>> table 'usno' and all indices (2).
>>
>> Nothing strange about it: that's how vacuum deals with large tables.
>> You can reduce the number of passes over the indexes by increasing
>> maintenance_work_mem (aka vacuum_mem). It looks like you have that
>> set to 16MB, which is enough to hold about 2.79M 6-byte CTIDs. When
>> that fills up, we have to go and clean out the corresponding index
>> entries before we resume scanning the heap.
>>
>
> I've increased maintenance_work_mem to 65536 (4x default value) and now I see
> postmaster eats more than 1Gb memory !
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 20458
> postgres 15 0 1350m 522m 204m D 8.0 51.6 1:08.26 postmaster
>
> Is this normal ? I've also increased checkpoint_segments to 12,
> but it shouldn't affect to memory.

Memory growth stoped at 1.8Gb

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
20458 postgres 15 0 1902m 503m 204m D 5.9 49.7 13:59.61 postmaster

>

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83