vacuum curiosity
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
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@xmission.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 pagesDETAIL: 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.