Re: Questions about guc units

On Sep 25, 2006, at 1:03 AM, Peter Eisentraut wrote:

> Am Montag, 25. September 2006 04:04 schrieb ITAGAKI Takahiro:
>> #shared_buffers = 32000kB       # min 128kB or max_connections*16kB
>> #temp_buffers = 8000kB          # min 800kB
>> #effective_cache_size = 8000kB
>>
>> Are there any reasons to continue to use 1000-unit numbers?  
>> Megabyte-unit
>> (32MB and 8MB) seems to be more friendly for users. It increases some
>> amount of values (4000 vs. 4096), but there is little in it.
>
> The reason with the shared_buffers is that the detection code in  
> initdb has
> 400kB as minimum value, and it would be pretty complicated to code the
> detection code to handle both kB and MB units.  If someone wants to  
> try it,
> though, please go ahead.

Seems like the unit used for shared_buffers (and others) should be  
megabytes then with a minimum of 1 (or more). Is less than 1MB  
granularity really useful here? On modern hardware 1MB of RAM is in  
the noise.

-Casey