Re: Extremely slow autovacuum:vacuum to prevent wraparound

[Rijo Roy <rjo_roy@xxxxxxxxx>]

No, I have  3 sessions of autovacuum against 3 tables which is doing a Vacuum to prevent wraparound as it hit the limit of autovacuum_freeze_max_age of 2 billion.

I also have a vaccumdb session which is invoked by me on these tables which is currently in paused state. So, I want to know whether I can kill the autivacuum sessions which is running since 5 days and extremely slow and just run a manual vacuum against these tables instead. 

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On Wed, 11 Jul 2018 at 6:36 pm, Ravi Krishna

<srkrishna@xxxxxxxxx> wrote:

Are you telling that you have multiple autovac on the same table?  If yes, that causes lock waits.

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On Jul 11, 2018, at 08:13 , Rijo Roy <rjo_roy@xxxxxxxxx> wrote:

Hi Ravi, 

It was the application teams call to disable it fearing the alteration of execution plans and slowness as per their explanation. I have joined 2 days back and I have tried educating them for enabling the same but they said after enough testing and evidence collected it will be enabled back in future.. 

As of now, I have started the manual vacuum operation on the databases but in one of them I am facing this issue that my vacuum jobs for 3 tables are paused as there are 3 autovacuum jobs running since 5 days on the same tables to prevent wraparound. 

Could you please confirm whether I can stop these autovacuum jobs so that I can run my manual run of vaccum job. 

Thanks, 

Rijo Roy 

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On Wed, 11 Jul 2018 at 5:37 pm, Ravi Krishna

<srkrishna@xxxxxxxxx> wrote:

Who disabled auto vacuum and why ?  Basically you are paying the price for it now 

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On Jul 11, 2018, at 7:33 AM, Rijo Roy <rjo_roy@xxxxxxxxx> wrote:

Hi Experts, 

I am running a PG10.4 in a RHEL 6.9. The tables stored in my database are mainly used for reads and very less writes happen. I have recently joined this environment and as soon as I logged into the postgresql servers, checked for dead tuples and relfrozenids.. And almost all have reached the autovacuum_freeze_max_age of 2billion and autovacuum was disabled.. Last vacuum was run 3 months back. 

Today I got permission to vacuum the tables but for 3 tables, Postgresql has already started the vacuum freeze using the autovacuum daemon running to prevent wraparound and these tables have TB'S of data.

Experts, please confirm whether I can kill these sessions and run a manual vacuum job with parallel jobs. 

Thanks in advance. 

Regards, 

Rijo Roy 

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