Rob Pikes 5 Rules of Programming:

Rule 1. You can't tell where a program is going to spend its time. Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is.

Rule 2. Measure. Don't tune for speed until you've measured, and even then don't unless one part of the code overwhelms the rest.

Rule 3. Fancy algorithms are slow when n is small, and n is usually small. Fancy algorithms have big constants. Until you know that n is frequently going to be big, don't get fancy. (Even if n does get big, use Rule 2 first.)

Rule 4. Fancy algorithms are buggier than simple ones, and they're much harder to implement. Use simple algorithms as well as simple data structures.

Rule 5. Data dominates. If you've chosen the right data structures and organized things well, the algorithms will almost always be self-evident. Data structures, not algorithms, are central to programming.

https://web.archive.org/web/20260314210910/https://users.ece...

It is often not worth optimising in the early days. You don't know how popular it will become, you might not know how many DNS records you will hold, it was possibly written in an earlier language and ported as-is.

At the point someone queries the 100TB of RAM, then maybe it is worth revisiting but even that has risks. You have to design the migration path, have fallback mechanisms etc.

Premature optimization argument fits right in. Now that memory is up to 10x more expensive it is worth considering optimizing programs with large memory footprint.

Discussing trivial optimizations is a waste of valuable design time. You're never going to "forget" an optimization. The running system will remind you when the optimization is actually needed.

Boxed slice isn't really the most well known type/optimization, There usually aren't that many vec's that it makes a big difference.

it was working so no one thought to check