Re: vacuum curiosity

>Does that suggest there is an open transaction?

No, it simply means there are zero/no dead rows that can be removed at that
time.
Please refer to the documentation on VACUUM, specifically 24.1.2.
Recovering Disk Space
<https://www.postgresql.org/docs/9.6/static/routine-vacuuming.html>

https://www.postgresql.org/docs/current/static/routine-vacuuming.html

<https://www.postgresql.org/docs/current/static/routine-vacuuming.html>

On Sun, Dec 17, 2017 at 1:20 PM, Rob Sargent <rsargent(at)xmission(dot)com> wrote:

> CAVEAT: I may have another version of this email bouncing around, sorry.
>
> Running PG10.0 on Centos 7.4
>
> I thought the current database was quiescent so I’m curious about the line
> isolated below with “0 dead row"
> Does that suggest there is an open transaction?
>
> vacuum (analyse, verbose) sui.segmentset_member;
> INFO: vacuuming "sui.segmentset_member"
> INFO: index "id_ordinal" now contains 20577332 row versions in 152802
> pages
> DETAIL: 0 index row versions were removed.
> 8264 index pages have been deleted, 8264 are currently reusable.
> CPU: user: 0.27 s, system: 1.31 s, elapsed: 13.29 s.
> INFO: index "segmentset_member_segment_id_idx" now contains 20577332 row
> versions in 105291 pages
> DETAIL: 0 index row versions were removed.
> 0 index pages have been deleted, 0 are currently reusable.
> CPU: user: 0.21 s, system: 0.93 s, elapsed: 7.02 s.
> INFO: "segmentset_member": found 0 removable, 16256972 nonremovable row
> versions in 135475 out of 171478 pages
>
> DETAIL: 0 dead row versions cannot be removed yet, oldest xmin: 2761
>
> There were 0 unused item pointers.
> Skipped 0 pages due to buffer pins, 0 frozen pages.
> 0 pages are entirely empty.
> CPU: user: 2.59 s, system: 4.37 s, elapsed: 41.46 s.
> INFO: analyzing "sui.segmentset_member"
> INFO: "segmentset_member": scanned 30000 of 171478 pages, containing
> 3599972 live rows and 0 dead rows; 30000 rows in sample, 20540396 estimated
> total rows
> VACUUM
> Time: 54948.217 ms
>

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.