Re: Cancelling of autovacuums considered harmful

On 02/26/2014 04:40 PM, Steve Crawford 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.

Oops, I meant to say the processes have an ANALYZE embedded in them but
this kills the vacuum. Typically they are bulk-loads into an empty table
followed by analysis and distribution of the incoming data to other
tables. The ANALYZE immediately follows the data load to ensure the
planner has updated stats for the analysis and other following stages.

Cheers,
Steve