pgsql-performance since 2025-11-10 00:00

Discussion of PostgreSQL's performance issues. Please see Guide to reporting problems and Slow Query Questions for some tips on how to write your performance question.

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Nov. 10, 2025

Thread Author Time
Multicolumn index scan efficiency Vitalii Tymchyshyn 02:44
Re: Multicolumn index scan efficiency Peter Geoghegan 04:20
Re: Multicolumn index scan efficiency Vitalii Tymchyshyn 05:12
Re: proposal: schema variables 📎 Pavel Stehule 06:40
Re: Multicolumn index scan efficiency Peter Geoghegan 17:00

Nov. 24, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 19:59
Re: proposal: schema variables 📎 Pavel Stehule 21:19

Nov. 25, 2025

Thread Author Time
Re: proposal: schema variables Pavel Stehule 04:43

Nov. 30, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 06:01

Dec. 3, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 04:27
Re: proposal: schema variables Jim Jones 13:44
Client-server communication for FETCH Tim Fors 18:02
Re: Client-server communication for FETCH Tom Lane 18:41
Re: Client-server communication for FETCH Tim Fors 19:45

Dec. 4, 2025

Thread Author Time
Why is my query 3 times faster on my workstation than on my server? Vincent Veyron 18:46
Re: Why is my query 3 times faster on my workstation than on my server? Pavel Stehule 18:53
Re: Why is my query 3 times faster on my workstation than on my server? Tom Lane 19:06
RE: Why is my query 3 times faster on my workstation than on my server? Clay Jackson (cjackson) 19:51
Re: Why is my query 3 times faster on my workstation than on my server? Vincent Veyron 22:56

Dec. 5, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 06:50
Re: Client-server communication for FETCH Jan Claeys 09:08
Seeking guidance on extremely slow pg_restore despite strong I/O performance MentionTheElephant 10:30
Re: Seeking guidance on extremely slow pg_restore despite strong I/O performance pg254kl 20:27

Dec. 6, 2025

Thread Author Time
Re: proposal: schema variables Jim Jones 11:29

Dec. 8, 2025

Thread Author Time
Re: Seeking guidance on extremely slow pg_restore despite strong I/O performance Jeff Janes 00:53
Re: proposal: schema variables 📎 Pavel Stehule 08:15
Re: proposal: schema variables 📎 Pavel Stehule 13:57

Dec. 9, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 05:51

Dec. 12, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 14:46

Dec. 15, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 04:42

Dec. 27, 2025

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 07:52

Jan. 2, 2026

Thread Author Time
Surprising optimizer behavior with a subquery, a GROUP BY, and a range filter wotq 20:26
Re: Surprising optimizer behavior with a subquery, a GROUP BY, and a range filter Tom Lane 20:46

Jan. 8, 2026

Thread Author Time
Unexpected planner choice in simple JOIN Mark Kirkwood 01:35
Re: Unexpected planner choice in simple JOIN Mark Kirkwood 03:34
Re: Unexpected planner choice in simple JOIN David Rowley 03:56
Re: Unexpected planner choice in simple JOIN Mark Kirkwood 04:03
Re: Unexpected planner choice in simple JOIN David Rowley 04:14
Re: Unexpected planner choice in simple JOIN Mark Kirkwood 04:24
Re: Unexpected planner choice in simple JOIN Tom Lane 04:34
Re: Unexpected planner choice in simple JOIN Mark Kirkwood 04:44
Re: Unexpected planner choice in simple JOIN Tom Lane 04:51
Re: Unexpected planner choice in simple JOIN Mark Kirkwood 04:55

Jan. 9, 2026

Thread Author Time
Another unexpected planner choice in simple JOIN Mark Kirkwood 00:12
Re: Another unexpected planner choice in simple JOIN Mark Kirkwood 01:15
Re: proposal: schema variables 📎 Pavel Stehule 08:45
Troubleshooting a brief spike in active sessions Dirschel, Steve-CW 21:41
Re: Troubleshooting a brief spike in active sessions Joshua Banton 21:58
Re: Troubleshooting a brief spike in active sessions Nikolay Samokhvalov 22:27
Re: Troubleshooting a brief spike in active sessions Nikolay Samokhvalov 22:29

Jan. 13, 2026

Thread Author Time
small database huge planning time 📎 Alexander Kulikov 09:16
Re: small database huge planning time Andrei Lepikhov 09:29
Re: small database huge planning time Greg Sabino Mullane 14:44
Re: small database huge planning time Huanbing Lu 16:07

Jan. 17, 2026

Thread Author Time
Slow queries on simple index Lillian Berry 13:58
Re: Slow queries on simple index Pavel Stehule 14:59
Re: Slow queries on simple index Ken Marshall 15:28
Re: Slow queries on simple index Tom Lane 16:57
Re: Slow queries on simple index Lillian Berry 19:33
Re: Slow queries on simple index Andrei Lepikhov 20:21
Re: Slow queries on simple index Lillian Berry 20:52
Re: Slow queries on simple index Tom Lane 21:10
[Solved] Slow queries on simple index Lillian Berry 22:06

Jan. 18, 2026

Thread Author Time
Re: Slow queries on simple index Andrei Lepikhov 09:24

Jan. 24, 2026

Thread Author Time
Re: small database huge planning time 📎 Andrei Lepikhov 22:12

Feb. 3, 2026

Thread Author Time
performance impact on read replicas during heavy vacuums on primary Dirk Krautschick 01:02

Feb. 4, 2026

Thread Author Time
Re: performance impact on read replicas during heavy vacuums on primary Greg Sabino Mullane 16:29

Feb. 10, 2026

Thread Author Time
Postgres IO sweet spot Riaan Stander 23:13

Feb. 11, 2026

Thread Author Time
LATERAL subquery predicate pushdown: filter applied after JSON construction instead of inside join (PG 18) 📎 Nyasha Chigwamba 16:12
Re: LATERAL subquery predicate pushdown: filter applied after JSON construction instead of inside join (PG 18) Tom Lane 17:37

Feb. 12, 2026

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 19:25

Feb. 16, 2026

Thread Author Time
A serious change in performance between PG 15 and PG 16, 17, 18. Clive Boughton 03:49
Re: A serious change in performance between PG 15 and PG 16, 17, 18. Tom Lane 04:03
Re: A serious change in performance between PG 15 and PG 16, 17, 18. David Rowley 04:04
Re: A serious change in performance between PG 15 and PG 16, 17, 18. David G. Johnston 04:04
Re: A serious change in performance between PG 15 and PG 16, 17, 18. Andrei Lepikhov 09:05
Re: Postgres IO sweet spot Riaan Stander 14:57
Re: Postgres IO sweet spot Greg Sabino Mullane 15:34
Re: A serious change in performance between PG 15 and PG 16, 17, 18. Joe Conway 15:42

Feb. 17, 2026

Thread Author Time
Re: Postgres IO sweet spot Riaan Stander 23:42

Feb. 18, 2026

Thread Author Time
Re: A serious change in performance between PG 15 and PG 16, 17, 18. David Rowley 00:01
Re: A serious change in performance between PG 15 and PG 16, 17, 18. Clive Boughton 01:05

Feb. 23, 2026

Thread Author Time
unstable query plan on pg 16,17,18 Attila Soki 09:37
Re: unstable query plan on pg 16,17,18 Laurenz Albe 09:41
Re: LATERAL subquery predicate pushdown: filter applied after JSON construction instead of inside join (PG 18) Nyasha Chigwamba 10:52
MERGE INTO... WHEN NOT MATCHED BY SOURCE index usage Lea Führer 14:18
Re: unstable query plan on pg 16,17,18 Attila Soki 15:10
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 15:54
Re: unstable query plan on pg 16,17,18 Attila Soki 17:03
Re: unstable query plan on pg 16,17,18 Laurenz Albe 19:59
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 20:25
Re: unstable query plan on pg 16,17,18 Attila Soki 20:42
Re: unstable query plan on pg 16,17,18 Laurenz Albe 20:54
Re: unstable query plan on pg 16,17,18 Attila Soki 21:19
Re: unstable query plan on pg 16,17,18 Laurenz Albe 21:44

Feb. 24, 2026

Thread Author Time
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 09:11
Re: unstable query plan on pg 16,17,18 Attila Soki 09:16
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 11:09
Re: unstable query plan on pg 16,17,18 Attila Soki 11:37
Re: unstable query plan on pg 16,17,18 Attila Soki 15:50
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 15:57
Re: unstable query plan on pg 16,17,18 Attila Soki 16:48
Re: unstable query plan on pg 16,17,18 📎 Andrei Lepikhov 19:20

Feb. 25, 2026

Thread Author Time
Re: MERGE INTO... WHEN NOT MATCHED BY SOURCE index usage Feike Steenbergen 16:35

Feb. 26, 2026

Thread Author Time
Re: unstable query plan on pg 16,17,18 Attila Soki 16:15
Re: unstable query plan on pg 16,17,18 Attila Soki 16:22
Re: unstable query plan on pg 16,17,18 Laurenz Albe 20:53

Feb. 27, 2026

Thread Author Time
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 08:15
Re: unstable query plan on pg 16,17,18 Attila Soki 15:00
Re: unstable query plan on pg 16,17,18 Andrei Lepikhov 15:35

March 4, 2026

Thread Author Time
Re: proposal: schema variables Haritabh Gupta 10:02
Re: proposal: schema variables Pavel Stehule 19:15

March 5, 2026

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 12:54
Planner join order regression from PG 15 to PG 16+: 70ms -> 1440ms (self-contained reproducer included) 📎 Mauro Gatti 16:25
Re: Planner join order regression from PG 15 to PG 16+: 70ms -> 1440ms (self-contained reproducer included) 📎 Andrei Lepikhov 19:09
Re: Planner join order regression from PG 15 to PG 16+: 70ms -> 1440ms (self-contained reproducer included) Tom Lane 21:44

March 6, 2026

Thread Author Time
Re: Planner join order regression from PG 15 to PG 16+: 70ms -> 1440ms (self-contained reproducer included) Mauro Gatti 08:24
Re: Planner join order regression from PG 15 to PG 16+: 70ms -> 1440ms (self-contained reproducer included) Andrei Lepikhov 09:05
Re: proposal: schema variables 📎 Pavel Stehule 09:06

March 10, 2026

Thread Author Time
Re: Postgres IO sweet spot Merlin Moncure 23:07

March 13, 2026

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 07:54

March 17, 2026

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 19:29
postgres chooses objectively wrong index Merlin Moncure 21:01
Re: postgres chooses objectively wrong index Alexey Ermakov 22:16
Re: postgres chooses objectively wrong index Tom Lane 22:24
Re: postgres chooses objectively wrong index Merlin Moncure 22:52

March 18, 2026

Thread Author Time
Re: postgres chooses objectively wrong index Alexey Ermakov 05:27
Re: proposal: schema variables 📎 Pavel Stehule 06:35
Re: postgres chooses objectively wrong index Merlin Moncure 18:38
Re: postgres chooses objectively wrong index Alexey Ermakov 20:12
Re: postgres chooses objectively wrong index Merlin Moncure 22:42

March 19, 2026

Thread Author Time
Re: postgres chooses objectively wrong index Andrei Lepikhov 07:09

March 23, 2026

Thread Author Time
Re: postgres chooses objectively wrong index Merlin Moncure 21:58

March 24, 2026

Thread Author Time
Re: postgres chooses objectively wrong index Andrei Lepikhov 09:21

March 25, 2026

Thread Author Time
Re: postgres chooses objectively wrong index Merlin Moncure 16:53

March 26, 2026

Thread Author Time
Re: proposal: schema variables 📎 Pavel Stehule 05:18

March 31, 2026

Thread Author Time
Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 09:28
Re: proposal: schema variables 📎 Pavel Stehule 11:07
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 12:03
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 17:55
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 18:06
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tom Lane 19:26
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 22:48

April 1, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 07:04
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 07:18
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 11:12
Potential partition pruning regression on PostgreSQL 18 Cándido Antonio Martínez Descalzo 11:56
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tom Lane 13:44
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 17:50
Re: Potential partition pruning regression on PostgreSQL 18 David Rowley 23:00

April 2, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 07:23
Re: Potential partition pruning regression on PostgreSQL 18 📎 Richard Guo 07:34
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 📎 Tom Lane 17:38
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Scott Carey 19:08
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tom Lane 22:03

April 3, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 📎 Frank Heikens 04:19
Re: proposal: schema variables 📎 Pavel Stehule 05:15
Re: proposal: schema variables 📎 Pavel Stehule 19:10
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tom Lane 19:24
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Jeff Davis 19:24
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Jeff Davis 19:36
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tom Lane 19:56
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Jeff Davis 20:01

April 4, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 00:21
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Tomas Vondra 12:18

April 6, 2026

Thread Author Time
Linux 7.0 performance degradation Rick Otten 14:12
Re: Linux 7.0 performance degradation Andreas Karlsson 14:59

April 7, 2026

Thread Author Time
Re: Potential partition pruning regression on PostgreSQL 18 📎 Richard Guo 08:00
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 Jeff Davis 21:58

April 9, 2026

Thread Author Time
Re: Potential partition pruning regression on PostgreSQL 18 Richard Guo 08:05
Async standby lag + physical slot + hot_standby_feedback=on appeared to degrade primary performance Priya V 22:39

April 11, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 02:09
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 02:42
how to switch user in postgres ikramuddin 17:55
Re: how to switch user in postgres Pavel Stehule 18:00
Re: how to switch user in postgres David G. Johnston 18:33
Re: how to switch user in postgres Tom Lane 19:29

April 14, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 📎 Jeff Davis 20:42

April 19, 2026

Thread Author Time
table bloat very fast and free space can not be reused James Pang 01:28
Re: table bloat very fast and free space can not be reused Christophe Pettus 03:56
Re: table bloat very fast and free space can not be reused James Pang 07:22
Re: table bloat very fast and free space can not be reused Kristjan Mustkivi 11:43

April 20, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 David Rowley 04:40
Re: table bloat very fast and free space can not be reused Rick Otten 14:39

April 21, 2026

Thread Author Time
Re: table bloat very fast and free space can not be reused Kristjan Mustkivi 08:33
feature request: index supported REINDEX for partial indexes on needle/haystack tables Merlin Moncure 17:22

April 27, 2026

Thread Author Time
Query performance Dirschel, Steve-CW 15:52

April 28, 2026

Thread Author Time
Re: Query performance Laurenz Albe 05:33

April 29, 2026

Thread Author Time
Re: Unexpected Seq Scan's when using MERGE WHEN NOT MATCHED BY SOURCE Viktor Holmberg 11:47

May 3, 2026

Thread Author Time
Postgres DB backup is taking too much time masheed ullah 09:42
Re: Postgres DB backup is taking too much time manish yadav 17:16

May 4, 2026

Thread Author Time
Re: Postgres DB backup is taking too much time Greg Sabino Mullane 00:20
Re: Postgres DB backup is taking too much time Ilya Anfimov 09:29
Re: Postgres DB backup is taking too much time masheed ullah 09:58
Re: Postgres DB backup is taking too much time 📎 Gerald Drouillard 10:10
Re: Postgres DB backup is taking too much time Ilya Anfimov 11:11
Re: Improving PostgreSQL insert performance Русинов Семен 18:03
Improving insert performance Русинов Семен 19:01
Re: Improving insert performance Laurenz Albe 20:49

May 5, 2026

Thread Author Time
Re: Significant performance issues with array_agg() + HashAggregate plans on Postgres 17 📎 Jeff Davis 01:27

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