Andrew Sullivan wrote:
> On Fri, Oct 17, 2003 at 07:04:45PM +0530, Shridhar Daithankar wrote:
>
>>I am slightly confused here. IIRC pg_autovacuum never did a vacuum full. At
>>the most it does vacuum /vacuum analyse, none of which chew disk bandwidth.
>
>
> The latter is false. VACUUM FULL certainly uses _more_ disk
> bandwidth than VACUUM, but it's just false that plain VACUUM doesn't
> contend for disk. And if you're already maxed, then that extra
> bandwidth you cannot afford.
What part of plain vacuum takes disk bandwidth? WAL? Clog? Certainly not data
files themselves, right?
OK, I understand some system can be saturated enough to have additional WAL/Clog
burdon, but genuinely curious, how much disk bandwidth is required for plain
vacuum and what are the factors it depends upon?
Shridhar