Re: Autovacuum on partitioned table (autoanalyze) - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Autovacuum on partitioned table (autoanalyze)
Date
Msg-id 20210809222549.jkfg4bh5xhww4teb@alap3.anarazel.de
Whole thread Raw
In response to Re: Autovacuum on partitioned table (autoanalyze)  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: Autovacuum on partitioned table (autoanalyze)  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
List pgsql-hackers
Hi,

On 2021-08-09 16:02:33 -0400, Alvaro Herrera wrote:
> On 2021-Jul-27, Andres Freund wrote:
> 
> > Isn't this going to create a *lot* of redundant sampling?  Especially if you
> > have any sort of nested partition tree. In the most absurd case a partition
> > with n parents will get sampled n times, solely due to changes to itself.
> 
> It seems to me that you're barking up the wrong tree on this point.
> This problem you describe is not something that was caused by this
> patch; ANALYZE has always worked like this.  We have discussed the idea
> of avoiding redundant sampling, but it's clear that it is not a simple
> problem, and solving it was not in scope for this patch.

I don't agree. There's a difference between this happening after a manual
ANALYZE on partition roots, and this continuously happening in production
workloads due to auto-analyzes...

Greetings,

Andres Freund



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