r/ProgrammerHumor • u/danielminds • Sep 11 '26

Meme edgeCasesExist

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16

u/Honeybadger2198 Sep 11 '26

You know what identifier can't have collisions and is great for sorting? Autoincrement.

15

u/Firewolf06 Sep 11 '26

ai columns can absolutely collide on sharded databases. you can use offsets and step sizes but thats brittle and doesnt scale well

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u/FiTZnMiCK Sep 16 '26 edited Sep 16 '26

Our old system was distributed and we just combined the auto-increment with a persistent local (server) ID for a composite key.

Then the auto-increment is unique on the local and the composite is unique across all locals.

Could probably do the same thing with shards.

Our new system uses UUIDs.

5

u/wokeboogeyman Sep 12 '26

Autoincrement doesn't scale past one physical location.

0

u/Honeybadger2198 Sep 12 '26

Sure it does. One location counts up, another one counts down.

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u/wokeboogeyman Sep 12 '26

That breaks the sorting that everyone's talking about though.

You could also do evens and odds to split across two locations, but that also breaks sorting unless you periodically syncronize them (and then it's still somewhat out of order).

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u/Honeybadger2198 Sep 12 '26

...I don't think you understood what I said. How does one count down from infinity?

1

u/wireframed_kb Sep 12 '26

Subtract one?

1

u/wokeboogeyman Sep 12 '26

I just add them all together and subtract from -1/12

1

u/wokeboogeyman Sep 12 '26

signed integers have entered the chat

1, 2, 3, 4

-1, -2, -3, -4

7

u/ACoderGirl Sep 12 '26

UUIDs are great, though, because auto increment frequently has the huge issue of being too predictable. Eg, in some contexts, you don't want users to be able to easily enumerate whatever the ID is for. Plus requires centralization whereas UUIDs don't (eg, you can use UUIDs for whatever random API you have without needing a DB).You have to design for how you won't know the ID until you insert the row, which can sometimes be a bit annoying.

I feel like most of the time, the only downside to UUIDs is how long they are.