Re: [HACKERS] GUC for cleanup indexes threshold. - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [HACKERS] GUC for cleanup indexes threshold.
Date
Msg-id CAA4eK1JQzRai_nnus9GKYye1tLHe5B_redjKcMGr-=i52ueLvQ@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] GUC for cleanup indexes threshold.  (Masahiko Sawada <sawada.mshk@gmail.com>)
Responses Re: [HACKERS] GUC for cleanup indexes threshold.  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
On Thu, Feb 23, 2017 at 5:15 PM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> On Wed, Feb 22, 2017 at 12:01 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
>> I understand that there could be some delay in reclaiming dead pages
>> but do you think it is such a big deal that we completely scan the
>> index for such cases or even try to change the metapage format?
>
> IIUC, I think that we need to have the number of half-dead pages in meta page.
>

Don't you think we need to consider backward compatibility if we want
to do that?

> Isn't it a problem that the freespace map of btree index is not
> vacuumed if all vacuums skip the second pass?
>

AFAIU, you want to skip only when there is no dead tuple removal, if
so what is the need to update freespace map of btree index?

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com



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