Re: Cancelling of autovacuums considered harmful

On Wed, Feb 26, 2014 at 5:40 PM, Steve Crawford
<scrawford(at)pinpointresearch(dot)com> wrote:
> On 02/26/2014 08:56 AM, Alvaro Herrera wrote:
>>
>> ...
>>
>> No matter how heavily updated, regular activity should not cause
>> autovacuum kills. Only heavier operations would do that (say ALTER
>> TABLE, etc).
>
>
> "Considered harmful" got my attention. What, if any, known harm is caused?
>
> We have many errors of this type but in our case most are due to batch
> processes that have a vacuum embedded at appropriate points in the string of
> commands in order to avoid excessive bloat and to ensure the tables are
> analyzed for the following steps. Occasionally the autovacuum triggers
> before the manual but gets canceled.
>
> Any harm?

We have some rather large tables that have never been autovacuumed. At
first I was thinking it was due to pgsql cancelling them due to load
etc. But if it's slony getting in the way then cancelling them is
still harmful, it's just not postgres' fault.