Re: Incorrect description of autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor

2018-09-27 Thread Martín Marqués
El jue., 27 sept. 2018 a las 18:05, Alvaro Herrera
() escribió:
>
> I suggest adding "This number is added to the number coming from the
> autovacuum_vacuum_scale_factor parameter for each table" just before the
> "This parameter can only be set" phrase.  So we'd end up with this:
>
> autovacuum_vacuum_threshold (integer)
> Specifies the minimum number of updated or deleted tuples needed to trigger a 
> VACUUM in any one table. The default is 50 tuples. This number is added to 
> the number coming from the autovacuum_vacuum_scale_factor parameter for each 
> table.  This parameter can only be set in the postgresql.conf file or on the 
> server command line; but the setting can be overridden for individual tables 
> by changing table storage parameters.
>
> autovacuum_vacuum_scale_factor (floating point)
> Specifies a fraction of the table size to add to autovacuum_vacuum_threshold 
> when deciding whether to trigger a VACUUM. The default is 0.2 (20% of table 
> size). This number is added to the autovacuum_vacuum_threshold parameter for 
> each table.  This parameter can only be set in the postgresql.conf file or on 
> the server command line; but the setting can be overridden for individual 
> tables by changing table storage parameters.

That looks very good IMO.

--
Martín Marqués
It’s not that I have something to hide,
it’s that I have nothing I want you to see



Re: Incorrect description of autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor

2018-09-27 Thread Alvaro Herrera
On 2018-Sep-27, PG Doc comments form wrote:

> Page: https://www.postgresql.org/docs/10/static/runtime-config-autovacuum.html
> 
> This page lists the different autovacuum options. Describing
> autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor independently
> adds confusion unless you are also reading
> https://www.postgresql.org/docs/10/static/routine-vacuuming.html#AUTOVACUUM
> where we have a formula for the threshold and scale factor.

True.

> I suggest adding a reference for each one of the two parameters with a link
> to the "Routine Vacuuming" section.

I suggest adding "This number is added to the number coming from the
autovacuum_vacuum_scale_factor parameter for each table" just before the
"This parameter can only be set" phrase.  So we'd end up with this:

autovacuum_vacuum_threshold (integer)
Specifies the minimum number of updated or deleted tuples needed to trigger a 
VACUUM in any one table. The default is 50 tuples. This number is added to the 
number coming from the autovacuum_vacuum_scale_factor parameter for each table. 
 This parameter can only be set in the postgresql.conf file or on the server 
command line; but the setting can be overridden for individual tables by 
changing table storage parameters.

autovacuum_vacuum_scale_factor (floating point)
Specifies a fraction of the table size to add to autovacuum_vacuum_threshold 
when deciding whether to trigger a VACUUM. The default is 0.2 (20% of table 
size). This number is added to the autovacuum_vacuum_threshold parameter for 
each table.  This parameter can only be set in the postgresql.conf file or on 
the server command line; but the setting can be overridden for individual 
tables by changing table storage parameters.

Same for the analyze parameters.

I suppose we don't need any updates to the section of
https://www.postgresql.org/docs/10/static/sql-createtable.html that
explains the equivalent reloptions, since those ones are very succint
anyway.

-- 
Álvaro Herrerahttps://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



Incorrect description of autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor

2018-09-27 Thread PG Doc comments form
The following documentation comment has been logged on the website:

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

This page lists the different autovacuum options. Describing
autovacuum_vacuum_threshold and autovacuum_vacuum_scale_factor independently
adds confusion unless you are also reading
https://www.postgresql.org/docs/10/static/routine-vacuuming.html#AUTOVACUUM
where we have a formula for the threshold and scale factor.

I suggest adding a reference for each one of the two parameters with a link
to the "Routine Vacuuming" section.