Re: autovacuum strategy / parameters

On Sat, May 1, 2010 at 1:08 PM, Robert Haas  wrote:
> On Sat, May 1, 2010 at 12:13 PM, Scott Marlowe  wrote:
>> On Fri, Apr 30, 2010 at 4:50 PM, Josh Berkus  wrote:
>>> Which is the opposite of my experience; currently we have several
>>> clients who have issues which required more-frequent analyzes on
>>> specific tables.   Before 8.4, vacuuming more frequently, especially on
>>> large tables, was very costly; vacuum takes a lot of I/O and CPU.  Even
>>> with 8.4 it's not something you want to increase without thinking about
>>> the tradeoff
>>
>> Actually I would think that statement would be be that before 8.3
>> vacuum was much more expensive.  The changes to vacuum for 8.4 mostly
>> had to do with moving FSM to disk, making seldom vacuumed tables
>> easier to keep track of, and making autovac work better in the
>> presence of long running transactions.  The ability to tune IO load
>> etc was basically unchanged in 8.4.
>
> What about http://www.postgresql.org/docs/8.4/static/storage-vm.html ?

That really only has an effect no tables that aren't updated very
often.  Unless you've got a whole bunch of those, it's not that big of
a deal.