Ask HN: What engineering trivia earned you the most cred

#1

Post by porkbrain » Wed, May 07, 2025, 5:48 PM UTC

Is there a specific piece of engineering knowledge that powered you to substantially contribute?

A software engineering example: knowing that Postgres FK doesn't implicitly create an index. Three different projects I joined weren't aware of this and we managed to improve the performance with a negligible amount of effort.

Keen to hear your wins (and make them mine ^^

Re: Ask HN: What engineering trivia earned you the most cred

#2

Post by catlover76 » Wed, May 07, 2025, 5:49 PM UTC

> knowing that Postgres FK doesn't implicitly create an index.

Damn really lol

What does it do then, just block "breaking" deletes?

Re: Ask HN: What engineering trivia earned you the most cred

#3

Post by porkbrain » Wed, May 07, 2025, 5:53 PM UTC

catlover76 wrote: post #2

> knowing that Postgres FK doesn't implicitly create an index. Damn really lol What does it do then, just block "breaking" deletes?

You can cascade the deletes in db layer rather than in app layer

Re: Ask HN: What engineering trivia earned you the most cred

#4

Post by catlover76 » Wed, May 07, 2025, 6:15 PM UTC

porkbrain wrote: post #3

catlover76 wrote: post #2

> knowing that Postgres FK doesn't implicitly create an index. Damn really lol What does it do then, just block "breaking" deletes?

You can cascade the deletes in db layer rather than in app layer

[dead]

Re: Ask HN: What engineering trivia earned you the most cred

#5

Post by austin-cheney » Thu, May 08, 2025, 9:38 AM UTC

Deeper internal knowledge of WebSockets and HTTP got me my current job.

Re: Ask HN: What engineering trivia earned you the most cred

#6

Post by deanmoriarty » Thu, May 08, 2025, 2:19 PM UTC

Every time I start doing some network packet-based troubleshooting, for example firing up tcpdump to debug a tcp window size improperly tuned that caused a performance degradation over a high latency link (this is a random example I did last week), coworkers look at me like I pulled off some sort of wizardry. I feel it’s knowledge that most SWEs working on distributed systems should have acquired early and routinely use, but clearly that’s not the case.