performance

Researching the Performance Puzzle

Posted by Jeremy ⋅ July 31, 2022 ⋅ 1 Comment

The PostgreSQL Performance Puzzle was, perhaps, too easy – it didn’t take long for someone to guess the correct answer! But I didn’t see much discussion about why the difference or what was happening. My emphasis on the magnitude of the difference was a tip-off that there’s much more than meets the eye with this … Continue reading →

PostgreSQL Performance Puzzle

Posted by Jeremy ⋅ July 16, 2022 ⋅ 15 Comments

Update 7/18: y’all guessed the answer to my puzzle very fast! At the bottom of this blog post, I’ve added the expressions that I used (with credit to those who guessed it), and also other expressions guessed by readers which exhibited similar behavior. I’ll do another follow-up blog post touching on several layers of this … Continue reading →

A Hairy PostgreSQL Incident

Posted by Jeremy ⋅ February 10, 2022 ⋅ 24 Comments

It was 5:17pm today, just as I was wrapping up work for the day, and my manager pinged me with the following chat: <manager>: Hi Jeremy – we have a <other team> ticket – escalated to <leader>, <leader>, etc. <principal> is on trying to advise as well. Are you available this evening if needed for … Continue reading →

Paranoid SQL Execution on Postgres

Posted by Jeremy ⋅ July 6, 2021 ⋅ 1 Comment

Suppose that you want to be completely over-the-top paranoid about making sure that when you execute some particular SQL statement on your Postgres database, you’re doing it in the safest and least risky way? For example, suppose it’s the production database behind your successful startup’s main commercial website. If anything even causes queries to block/pause … Continue reading →

Column And Table Redefinition With Minimal Locking

Posted by Jeremy ⋅ November 8, 2018 ⋅ 1 Comment

TLDR: Note to future self… (1) Read this before you modify a table on a live PostgreSQL database. If you do it wrong then your app might totally hang. There is a right way to do it which avoids that. (2) Especially remember the lock_timeout step. Many blog posts around the ‘net are missing this … Continue reading →

This Week in PostgreSQL – May 31

Posted by Jeremy ⋅ June 4, 2018

Since last October I’ve been periodically writing up summaries of interesting content I see on the internet related to PostgreSQL (generally blog posts). My original motivation was just to learn more about PostgreSQL – but I’ve started sharing them with a few colleagues and received positive feedback. Thought I’d try posting one of these digests … Continue reading →

Understanding CPU on AIX Power SMT Systems

Posted by Jeremy ⋅ July 1, 2016 ⋅ 6 Comments

This month I worked with a chicagoland company to improve performance for eBusiness Suite on AIX. I’ve worked with databases running on AIX a number of times over the years now. Nevertheless, I got thrown for a loop this week. TLDR: In the end, it came down to a fundamental change in resource accounting that … Continue reading →

November/December Highlights

Posted by Jeremy ⋅ January 2, 2014 ⋅ 1 Comment

In the Oracle technical universe, it seems that the end of the calendar year is always eventful. First there’s OpenWorld: obviously significant for official announcements and insight into Oracle’s strategy. It’s also the week when many top engineers around the world meet up in San Francisco to catch up over beers – justifying hotel and … Continue reading →