Top all-time · #758
Robert Haas
Personal blog · rhaas.blogspot.comprogrammingdatasystems
Robert Haas's personal blog at rhaas.blogspot.com covers programming, data and systems. Since 2010, 86 different Hacker News readers have linked it 135 times, most often “Postgres 9.2 will feature linear read scalability up to 64 cores”. It is still writing: the last post was on 2026-10-30, and you can follow it by feed.
Rarely recommended · 3 of 39 sampled comments recommend it?
Why HN links it
Linked as a reference for PostgreSQL internals and history: vacuum, scalability benchmarks, parallel query, MySQL comparisons and the pg_plan_advice design. Comments mostly cite it for explanation.
- Recommended for · 3 comments
- Called an excellent post on MySQL vs PostgreSQL, and the pg_plan_advice post worth reading for its motivation and design; another points to posts on incremental
Summarised by Claude from a sample of 39 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Sr. Staff Software Engineer @ Databricks, PostgreSQL Major Contributor and Committer
Most-linked posts?
- Postgres 9.2 will feature linear read scalability up to 64 cores6 people · 6 mentions · first linked 2012-04-03
- Pg_plan_advice: Plan stability and user planner control for PostgreSQL?6 people · 6 mentions · first linked 2026-03-05
- Why Pg_dump Is Amazing6 people · 6 mentions · first linked 2024-11-01
- Parallel Sequential Scan for PostgreSQL 9.55 people · 5 mentions · first linked 2015-03-18
- Do or undo – there is no VACUUM5 people · 5 mentions · first linked 2018-01-30
- Parallel Sequential Scan is Committed to PostgreSQL 9.64 people · 4 mentions · first linked 2015-11-11
- Praise, Criticism, and Dialogue on Postgres mailing list3 people · 3 mentions · first linked 2023-12-20
- Robert Haas: MySQL vs. PostgreSQL, Part 2: VACUUM vs. Purge3 people · 3 mentions · first linked 2011-02-02
- Linux's fsync() woes are getting some attention2 people · 2 mentions · first linked 2014-03-10
- How index-only scans will help PostgreSQL 2 people · 2 mentions · first linked 2010-11-23
What Hacker News says?
> Sure, it mightn't be made in this thread yet, but that doesn't make it an irrelevant, invalid, or uninteresting observation. I really think it does. It's like "the sky isn't green!" or "the earth isn't flat!" or "vaccines don't cause autism!" Sure, these are all true things, but they weren't exactly topics of discussion on this thread before you brought them up. By all means, discuss the article, and rebut comment…
Comment linking /2014/03/linuxs-fsync-woes-are-getting-some.html
on “PostgreSQL used fsync incorrectly for 20 years”Submitted New Features Coming in PostgreSQL 10 as a story · 517 points
HN discussionHmm, wonder why they didn't try FoundationDB. Interesting that they had problems with vacuuming. I always thought that part of Postgres was the worst part. I vaguely remember that you needed twice the space to vacuum successfully, which hopefully has changed in later versions. An article about why vacuum is needed in pg (as compared to mysql/innodb). http://rhaas.blogspot.com/2011/02/mysql-vs-postgresql-part-2...
Comment linking /2011/02/mysql-vs-postgresql-part-2-vacuum-vs.html
on “How Figma's databases team lived to tell the scale”Submitted No More Full Table Vacuums in PostgreSQL as a story · 290 points
HN discussionReplication across major versions, for example to upgrade without downtime. Partial replication, to distribute shared data across a series of clusters, or for analytics and reporting as you mention. Replicating the data without replicating any table bloat. Being able to do limited writes (e.g. to temporary tables) on the standby. http://rhaas.blogspot.com/2011/02/case-for-logical-replicati...
Comment linking /2011/02/case-for-logical-replication.html
on “New Features Coming in PostgreSQL 10”Submitted Parallel Sequential Scan is Committed to PostgreSQL 9.6 as a story · 275 points
HN discussionFor future reference, I have found this excellent post about the same topic https://rhaas.blogspot.com/2011/02/mysql-vs-postgresql-part-...
Comment linking /2011/02/mysql-vs-postgresql-part-2-vacuum-vs.html
on “Things we learned running Postgres 13”Submitted PostgreSQL Parallel Query v2 as a story · 265 points
HN discussionThis is from 2012: http://rhaas.blogspot.com/2012/04/did-i-say-32-cores-how-abo... My guess is the 1 socket options scales great. 2 sockets are are less than ideal, and you will not double the 1 socket performance.
Comment linking /2012/04/did-i-say-32-cores-how-about-64.html
on “AMD Prepares 32-Core Naples CPUs for 1P and 2P Servers: Coming in Q2”Submitted Postgres 9.2 will feature linear read scalability up to 64 cores as a story · 262 points
HN discussion(OP here, happy to see this on HN!) If you're interested in this topic, Robert Haas (the author/committer of the feature) also wrote two posts after I published this, which talk more about incremental backup: http://rhaas.blogspot.com/2024/01/incremental-backup-what-to... http://rhaas.blogspot.com/2024/01/incremental-backups-evergr...
Comment linking /2024/01/incremental-backups-evergreen-and-other.html
on “Postgres Incremental Backup”Submitted Plans for partitioning in PostgreSQL v11 as a story · 241 points
HN discussionI doubt that's possible, for a number of reasons. 1) Neither company owns any part of the PostgreSQL code / docs. We do have various proprietary tools, of course, but so do other companies. 2) The companies employ quite a few PostgreSQL hackers, but if you look at the development stats (e.g. http://rhaas.blogspot.com/2020/05/who-contributed-to-postgre... ) you'll see there are many committers and developers in other…
Comment linking /2020/05/who-contributed-to-postgresql.html
on “PostgreSQL community impact of 2nd Quadrant purchase”Submitted PostgreSQL's Hash Indexes Are Now Cool as a story · 214 points
HN discussionIf you're looking for a good series of blog posts about xid wraparound in Postgres check out these posts by Josh Berkus: http://www.databasesoup.com/2012/09/freezing-your-tuples-off... http://www.databasesoup.com/2012/10/freezing-your-tuples-off... http://www.databasesoup.com/2012/12/freezing-your-tuples-off... And this more recent one by Robert Haas: https://rhaas.blogspot.com/2018/01/the-state-of-vacuum.html As Jo…
Comment linking /2018/01/the-state-of-vacuum.html
on “Mandrill has been down for over 30 hours with no explanation”Submitted The State of Vacuum in Postgres as a story · 169 points
HN discussionI'm not sure why this comment is downvoted. The behavior of PostgreSQL on workloads that require vacuuming of large tables -- and especially the default behavior in that case -- is hugely problematic. There's a major project ongoing to build a new storage engine to address this: http://rhaas.blogspot.com/2018/01/do-or-undo-there-is-no-vac... Like you, I've long wished I could pay a performance penalty on queries to…
Comment linking /2018/01/do-or-undo-there-is-no-vacuum.html
on “Simple script to analyse your PostgreSQL database config, give tuning advice”Submitted Hacking on PostgreSQL is hard as a story · 159 points
HN discussionBlog post with some details and benchmarks by one of the authors of the patch: http://rhaas.blogspot.com/2015/11/parallel-sequential-scan-i...
Comment linking /2015/11/parallel-sequential-scan-is-committed.html
on “Postgresql 9.6: Support parallel aggregation”Submitted Do or undo – there is no VACUUM as a story · 139 points
HN discussionhttp://rhaas.blogspot.com/2011/02/mysql-vs-postgresql-part-2...
Comment linking /2011/02/mysql-vs-postgresql-part-2-vacuum-vs.html
on “Why does everyone run ancient Postgres versions?”Submitted Linux's fsync() woes are getting some attention as a story · 135 points
HN discussionYep, see http://rhaas.blogspot.com/2010/11/mysql-vs-postgresql-part-1...
Comment linking /2010/11/mysql-vs-postgresql-part-1-table.html
on “Postgres 9.2 will feature linear read scalability up to 64 cores”Submitted Uber's Move Away from PostgreSQL as a story · 119 points
HN discussionWell PostgreSQL does scale to millions of simple read-only transactions per minute, at least in some benchmarks. And in PostgreSQL 9.2 it will scale much better, in the synthetic benchmark it reached about 13 million per minute at high concurrency (compared to about 2.5 million for 9.1). http://rhaas.blogspot.com/2011/09/scalability-in-graphical-f...
Comment linking /2011/09/scalability-in-graphical-form-analyzed.html
on “The key value store we ignored (Postgresql)”Submitted Who Contributed to PostgreSQL Development in 2020 and 2021? as a story · 101 points
HN discussionThis was fixed in PG 10 (Oct 2017). See https://rhaas.blogspot.com/2017/09/postgresqls-hash-indexes-...
Comment linking /2017/09/postgresqls-hash-indexes-are-now-cool.html?m=1
on “How does database indexing work? (2008)”Submitted Hacking on PostgreSQL Is Hard as a story · 95 points
HN discussionNo, it's not. The referenced article is talking about Postgres 9.2devel. Version 9.2 isn't out yet, and even if it was, it still wouldn't be true due to the clause "and has done so for a few years". The lock manager bottlenecks that stopped PG from using more than 60% of the cpu power on a 24 core box were discovered a little less than a year ago. http://rhaas.blogspot.com/2011/07/read-scaling-out-to-32-cor...
Comment linking /2011/07/read-scaling-out-to-32-cores.html
on “Goodbye, CouchDB”Submitted Why The Clock is Ticking for MongoDB as a story · 92 points
HN discussion
