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Powered by muscle cells, a paper-thin robot swims through watery maze

https://news.mit.edu/2026/powered-by-muscle-cells-paper-thin-robot-swims-through-watery-maze-0929
1•gmays•2m ago•0 comments

SpiritFone Session

http://spirititc.org/2026/11/06/spiritfone-in-action/
1•pkshadygrove•4m ago•0 comments

17776 (2017)

https://www.sbnation.com/a/17776-football
1•akkartik•4m ago•0 comments

Connect ChatGPT or Claude to Wordpress.com, Free in November

https://wordpress.com/blog/2026/11/03/free-chatgpt-claude/
1•rdmuser•6m ago•0 comments

California Voters Reject Billionaire Wealth Tax, DDHQ Projects

https://www.bloomberg.com/news/articles/2026-11-07/california-voters-reject-billionaire-tax-ddhq-...
2•madihaa•6m ago•0 comments

Naval Ravikant: The Beginning of Infinity [video]

https://www.youtube.com/watch?v=yAj5EnyuakI
1•jakeogh•7m ago•0 comments

Just turned my car into a Tesla Roadster

https://roadster-chi.vercel.app/
1•aaron_dutta•10m ago•0 comments

Meta Employees 'Interacted' with Pirated Copies of Adult Films, Filing Shows

https://torrentfreak.com/meta-employees-interacted-with-pirated-copies-of-adult-films-filing-shows/
2•gslin•11m ago•0 comments

A barbarian tribe's mythic origin story is true, ancient DNA reveals

https://www.science.org/content/article/barbarian-tribe-s-mythic-origin-story-true-ancient-dna-re...
1•benbreen•19m ago•0 comments

Code Matters: Reflections on Rust in the LLM Age – Bryan Cantrill – Rust NYC [video]

https://www.youtube.com/watch?v=5D7QPOIZ7gY
2•vismit2000•19m ago•0 comments

Show HN: Help me pick a logo animation for my in-browser AI creature game

https://id-le.com/review/intro-logo-animation
1•nico•20m ago•0 comments

We Engineer Safer Agents

https://www.perplexity.ai/hub/blog/how-we-engineer-safer-agents
1•gmays•21m ago•0 comments

Quantum Computers Are Poised to Crack Encryption. AI Could Beat Them to It

https://www.wsj.com/tech/ai/ai-math-online-encryption-quantum-computers-57926bb2
1•fortran77•34m ago•0 comments

Exploring Janet and the HTTPF web framework

https://nick.gs/blog/2026-11/exploring-janet-and-the-httpf-web-framework/
1•veqq•35m ago•0 comments

F2FS: A New File System for Flash Storage (2015) [pdf]

https://www.usenix.org/system/files/conference/fast15/fast15-paper-lee.pdf
1•vismit2000•38m ago•0 comments

Show HN: We tested our prompt injection filter in public

https://hodor.gatebolt.com/blog/secret-leak-test
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MCP-server-AutoCAD-Lisp-helper

https://github.com/radwanalmsora/mcp-server-autocad-lisp-helper
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The AI Business Model Just Collapsed

https://www.honest-broker.com/p/the-ai-business-model-just-collapsed
3•paulpauper•43m ago•1 comments

Why do people see colours differently? Sometimes, it's the display's fault

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GLP-1 Prescriptions for People with No Medical Need Are Climbing

https://www.nytimes.com/2026/09/22/well/ozempic-glp1-medical-reason.html
2•paulpauper•47m ago•1 comments

The Pangram Backlash Unfolding on College Campuses

https://www.theatlantic.com/technology/2026/09/college-professors-ai-detectors-pangram/688727/
2•paulpauper•49m ago•0 comments

US believes Nvidia's Huang had romantic relationship with alleged Chinese spy

https://www.ft.com/content/a55a2a22-4479-4f93-a445-6147a5c6d790
5•robbiet480•50m ago•0 comments

Adding proper security to your vibecoded Linux GUI apps

https://akitaonrails.com/en/2026/11/06/adding-proper-security-to-your-vibecoded-linux-gui-apps/
1•ayanb9440•51m ago•0 comments

HomeMinerProxy: home dashboard and Stratum proxy for Bitcoin lottery mining

https://github.com/Modanez/HomeMinerProxy
1•modanez•59m ago•0 comments

What do workers want in a leader? New study challenges stereotypes

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3•rohanm93•59m ago•0 comments

SpaceX's $2T Bet Has a Physics Problem [video]

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Show HN: S3mail – Serverless personal email on AWS with JMAP

https://github.com/zero11-0203/s3mail
1•zero11-0203•1h ago•0 comments

Killer App, the thrilling story about the rise of Telegram

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1•elies•1h ago•0 comments

Geometry, Kinematics, Statics, and DYNAMICS(2018) [pdf]

http://ruina.tam.cornell.edu/Courses/ME4730%20Fall%202018/books/Dynamics_Book_Bernstein__Goel__An...
1•pillars•1h ago•0 comments

Show HN: Promptcheckup – pass/fail check for prompt changes, with 95% intervals

https://github.com/gael55x/promptcheckup
1•gael55x•1h 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?