Re: How can i be certain autovacuum is causing reuse if table still grows

So you can use your SERIAL (or GENERATED AS IDENTITY) column for this. If you don't have this, you might add a DATE DEFAULT CURRENT_DATE column, even if it's of no use except being the partition key.

Any key that "increases linearly over time" is a chronological key; sequences are a perfect example.

On 7/27/20 4:38 PM, Sidney Aloisio Ferreira Pryor wrote:

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Thank you Ron but this table has no date column.

It has one line for each page of each scanned document.

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De: Ron <ronljohnsonjr@gmail.com>
Enviado: segunda-feira, 27 de julho de 2020 18:27
Para: pgsql-admin@lists.postgresql.org <pgsql-admin@lists.postgresql.org>
Assunto: Re: How can i be certain autovacuum is causing reuse if table still grows

 

Another suggestion is to partition the table by a chronological key, so that only a fraction of the table needs to be vacuumed.

On 7/27/20 3:36 PM, Sidney Aloisio Ferreira Pryor wrote:

Thank you, David.

So can i assume that autovacuum only release dead tuples when it ends its execution?

Autovacuum is not finishing and is running for days.

We did not find a parameter to limit autovacuum executing time.

Do you have any recomendation?

Thank you.

Sidney.

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De: David G. Johnston <david.g.johnston@gmail.com>
Enviado: segunda-feira, 27 de julho de 2020 17:17
Para: Sidney Aloisio Ferreira Pryor <sidney@tjrj.jus.br>
Cc: pgsql-admin@lists.postgresql.org <pgsql-admin@lists.postgresql.org>
Assunto: Re: How can i be certain autovacuum is causing reuse if table still grows

 

On Monday, July 27, 2020, Sidney Aloisio Ferreira Pryor <sidney@tjrj.jus.br> wrote:

Hi, we have a 9.6.5 postgres

 

Autovacuum is set with default parameters and is running on this table for days without naping or stopping.

 3285 | -5 days -23:33:10.792166 | postgres | autovacuum: VACUUM ANALYZE public.flip_pagina_edicao (to prevent wraparound)

(1 rows)

Its probably best avoid drawing conclusions here until the anti-wraparound vacuum has completed and you’ve updated to the latest minor version of PostgreSQL.

David J.

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