Обсуждение: Difference between "autovacuum_naptime" and "autovacuum_vacuum_cost_delay"?

Hi All,

I have gone through several documents but I am still have confusion related to "autovacuum_naptime" and "autovacuum_vacuum_cost_delay". Could you clarify me with an example.

When Auto vacuum worker process will start?

Autovacuum checks for relations that need to be vacuumed/analyzed every "naptime"

When Auto vacuum worker process will stop?

When it is done with the list of relations that needed work that were found at the launch of "naptime"

Does Auto vacuum worker process will sleep like Auto vacuum launcher process ?

The launcher process sleeps for naptime, then wakes up to check what needs to be worked on

What is the difference between Auto vacuum launcher process and Auto vacuum worker process?

The launcher is the process that spawns the worker processes (I think).

JD

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Regards,
Raghavendra Rao J S V

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On 08/16/2018 09:42 PM, Raghavendra Rao J S V wrote:
> Thank you very much for your response.
> 
> Could you clarify me below things,please?

The docs can:

https://www.postgresql.org/docs/10/static/routine-vacuuming.html#AUTOVACUUM

https://www.postgresql.org/docs/10/static/runtime-config-autovacuum.html

> 
> What is the difference between "autovacuum_naptime" and 
> "autovacuum_vacuum_cost_delay"?
> 
> What is the difference between "autovacuum launcher process" and 
> "autovacuum worker process"?
> 
> How to control the number of "autovacuum launcher process" and 
> "autovacuum worker process"?
> 
> Does "autovacuum launcher process" sleeps? If yes,which parameter 
> controls it?
> 
> Does "autovacuum worker process" sleeps? If yes,which parameter controls it?
> 
> Regards,
> Raghavendra Rao
> 
> 
> On 17 August 2018 at 09:30, Joshua D. Drake <jd@commandprompt.com 
> <mailto:jd@commandprompt.com>> wrote:
> 
>     On 08/16/2018 06:10 PM, Raghavendra Rao J S V wrote:
>>     Hi All,
>>
>>     I have gone through several documents but I am still have
>>     confusion related to "autovacuum_naptime" and
>>     "autovacuum_vacuum_cost_delay". Could you clarify me with an example.
>>
>>     When Auto vacuum worker process will start?
>>
> 
>     Autovacuum checks for relations that need to be vacuumed/analyzed
>     every "naptime"
> 
>>     When Auto vacuum worker process will stop?
> 
>     When it is done with the list of relations that needed work that
>     were found at the launch of "naptime"
> 
>>
>>     Does Auto vacuum worker process will sleep like Auto vacuum
>>     launcher process ?
> 
>     The launcher process sleeps for naptime, then wakes up to check what
>     needs to be worked on
> 
>>
>>     What is the difference between Auto vacuum launcher process and
>>     Auto vacuum worker process?
> 
>     The launcher is the process that spawns the worker processes (I think).
> 
>     JD
>>
>>
>>
>>     -- 
>>     Regards,
>>     Raghavendra Rao J S V
>>
> 
>     -- 
>     Command Prompt, Inc. ||http://the.postgres.company/  || @cmdpromptinc
>     ***  A fault and talent of mine is to tell it exactly how it is.  ***
>     PostgreSQL centered full stack support, consulting and development.
>     Advocate: @amplifypostgres || Learn:https://postgresconf.org
>     *****     Unless otherwise stated, opinions are my own.   *****
> 
> 
> 
> 
> -- 
> Regards,
> Raghavendra Rao J S V
> Mobile- 8861161425


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