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Incident with Pages GitHub

https://www.githubstatus.com/incidents/5bnwwg9tzd4q
1•prakashqwerty•2m ago•0 comments

Ask HN: Does anyone use Google's Jules?

1•baddash•2m ago•0 comments

Timescapes of Non-Human Experience

https://www.sciencedirect.com/science/article/pii/S1364661326001087?dgcid=author#f0005
1•XzetaU8•3m ago•0 comments

Show HN: AI Infrastructure Knowledge Base

https://ai-infrastructure.net/
1•hevalon•3m ago•0 comments

Leak: Microsoft created Edge-based Copilot OS wih AI-powered UI, no Start menu

https://www.windowslatest.com/2026/07/02/watch-leak-from-2024-shows-off-microsofts-copilot-os-for...
1•Abhijith__MB•3m ago•0 comments

What if AGI is here, but it just actually sucks?

1•arm32•5m ago•2 comments

Amsterdam Invented the Fire Department

https://worksinprogress.co/issue/how-amsterdam-invented-the-fire-department/
1•deunamuno•7m ago•0 comments

Indians using app to shut down e-rickshaws in the middle of roads

https://timesofindia.indiatimes.com/etimes/trending/can-kill-people-indians-are-using-a-chinese-a...
1•astroanax•8m ago•0 comments

Sports Rightsholders Want an EU ASN/IP Blacklist for 'Piracy' Hosting Providers

https://torrentfreak.com/sports-rightsholders-want-an-eu-blacklist-for-piracy-hosting-providers/
2•iamnothere•9m ago•2 comments

Ask HN: What's the simplest way for me to get my AMEX data agentically?

2•artur_makly•10m ago•0 comments

CMA CGM to Buy FedEx Supply Chain for $1.4B

https://www.wsj.com/business/logistics/french-shipping-company-cma-cgm-to-buy-fedex-supply-chain-...
2•petethomas•11m ago•0 comments

Weird Al Yankovic Pulled Out of AI Ad Deal: 'I Can't Be the Poster Boy for AI'

https://variety.com/2026/biz/news/weird-al-yankovic-rejected-ai-commercial-money-offer-1236800794/
1•fortran77•11m ago•0 comments

The Download: a startup has a solution for AI's groupthink problem

https://www.technologyreview.com/2026/07/02/1140027/the-download-ai-groupthink-llms/
1•joozio•12m ago•0 comments

The Elon Musk boycott is fizzling out–and Tesla is winning again

https://www.msn.com/en-us/autos/news/the-elon-musk-boycott-is-fizzling-out-and-tesla-is-winning-a...
2•petethomas•13m ago•0 comments

For Sale: AI platform for creating viral short-form videos

https://flippa.com/13365327-ai-powered-video-generation-platform-for-creating-viral-short-form-co...
1•kilincarslan•13m ago•0 comments

Russia is using drones from the war in Ukraine in Africa

https://www.france24.com/en/africa/20260702-unprecedented-images-russia-using-drones-war-ukraine-...
2•loandbehold•13m ago•0 comments

Show HN: Flashtype – Markdown editor for Claude and Codex with in-line diffs

https://flashtype.com/
3•samuelstros•14m ago•0 comments

Cloudflare fronts 42% of indie launches. It's also at 42% of the Fortune 500

https://stackscope.dev/blog/state-of-indie-launches-june-2026
1•datafreak_•14m ago•0 comments

Agents collaboratively writing a wiki on RL for LLMs

https://huggingface.co/spaces/rl-llm-wiki/rl-dashboard
1•victormustar•14m ago•0 comments

Cisco confirms attackers exploiting Unified CM flaw

https://www.bleepingcomputer.com/news/security/cisco-finally-confirms-attackers-exploiting-unifie...
3•Brajeshwar•15m ago•0 comments

Gen Z Was Told We Could Save the World. Is It Silly to Think We Still Can?

https://www.teenvogue.com/story/gen-z-was-told-we-could-save-the-world-is-it-silly-to-think-we-st...
1•Tomte•18m ago•0 comments

Thinking Machines' Interaction Models

https://blog.bytebytego.com/p/inside-thinking-machines-interaction
1•gmays•19m ago•0 comments

Excommunication decreed for Lefebvrite episcopal ordinations

https://www.vaticannews.va/en/vatican-city/news/2026-07/holy-see-decrees-excommunication-lefebria...
2•haunter•19m ago•0 comments

Ask HN: What are you go to LLM models for the following

1•mrburton•20m ago•0 comments

Who should the U.S. Talk to in China on AI?

https://mattsheehan.substack.com/p/who-should-the-us-talk-to-in-china
1•taiwandongsuan•22m ago•0 comments

Show HN: Who wants to be hired?" meets "Who is hiring?" (July 2026)

https://hn-job-match-production.up.railway.app/
1•lellow•23m ago•0 comments

Back end-for-Front end: The most secure architecture for browser-based apps

https://fusionauth.io/blog/backend-for-frontend-security-architecture
2•mooreds•23m ago•0 comments

A Unique Strategy for Creating and Crowdfunding Games: 6 Questions

https://stonemaiergames.com/34671-2/
1•Tomte•24m ago•0 comments

Europe's top court upholds Google's record $4.7B antitrust fine

https://www.neowin.net/news/europes-top-court-upholds-googles-record-47-billion-antitrust-fine/
3•bundie•24m ago•2 comments

Linux kernel archives temporarily unavailable, fix has been implemented

https://social.kernel.org/notice/B7viUNMy1UsGX9pwHY
1•infinet•25m ago•0 comments
Open in hackernews

Ask HN: How can I load test PostgreSQL but avoid changing actual data?

1•LawZiL•1y ago
I'm running a load test on my Node.js application and want to simulate realistic write-heavy scenarios to stress test the system — especially the PostgreSQL database.

There's a part of the code that performs UPDATE queries, but during load testing, I don't want these updates to actually change the state of the database. However, I still want the database to experience the full impact of the update — query planning, locking, I/O, WAL writes, etc. — so I can measure how it affects performance under peak load.

Is there a best-practice approach to achieve this?

So far, the most viable option I’ve found is to wrap the UPDATE queries in a transaction and then roll it back — that way, the queries still execute, but the state doesn’t change. Is this the right way to go? Does rollback introduce any performance overhead that would skew my results? Are there better or more realistic alternatives that simulate the full write path without persisting changes?

Thanks in advance!

Comments

sargstuff•1y ago
pgbench[2] / pgreplay-go[0] / python locust[1]

very old school approach:

Misuse sql VIEW[3][4] to generate a temporary parallel table setup. Testing database separate from production database would be 'better', IMHO.

-----

[0] pgreplay-go : https://github.com/gocardless/pgreplay-go

[1] python locust : https://miguel-codes.medium.com/unconventional-load-testing-...

[2] pgbench load testing :

   a) https://medium.com/@c.ucanefe/pgbench-load-test-166bdfb5c75a

   b) https://neon.tech/blog/autoscaling-in-action-postgres-load-testing-with-pgbench

   c) https://hackernoon.com/how-to-create-and-load-test-data-in-postgresql-i41e353m
----------------------------

[3] : a) https://hashrocket.com/blog/posts/materialized-view-strategi...

      b) https://tech.jonathangardner.net/wiki/PostgreSQL/Materialized_Views

      c) https://stackoverflow.com/questions/77603705/what-is-the-use-of-materialized-view-in-postgresql
[4] : https://en.wikipedia.org/wiki/View_(SQL)
LawZiL•1y ago
but again, how can i perform the query, but not actually change the state, i really need the state to keep untouched, but be able to perform the query itself.
MatthiasPortzel•1y ago
> Does rollback introduce any performance overhead that would skew my results?

I would expect it to be the other way around—since the transactions are rolled back and not committed, they would have significantly less performance impact. But I’m working from an academic model of the database.

apothegm•1y ago
Load test against a clone instead of a DB whose contents you care about?