text/gemini: New post: Universal Unique Identifies are good, use them

text/gemini/src/2024-04-03.1.gmi

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+# Universal Unique Identifies are good, use them
+
+There is a thing called Universal Unique Identifier (UUID). It is a
+way to randomly generate 128 bit number that it won't coincide¹ with
+any other number generated using the same algorithm; no coordination
+authority needed.
+
+It sounds like a magic, but it works. Actually, git does something
+similar: independently made commits never¹ collide.
+
+Unlike more convention idea of enumerating things with integers,
+UUID's have multiple advantages:
+
+1. They can be assigned by client. This allows greater level of
+   parallelization.
+
+   For example, if GitHub pull requests were using UUID's, API call to
+   make a pull request and API call to make an issue mentioning that
+   pull request could have been done in parallel. Since pull requests
+   are numbers, the only way to get pull request number is to wait for
+   the API call creating it.
+
+2. When some object is imported from one system to another, UUID's can
+   be imported as-is, while numbers require keeping track of the
+   mapping between different numeric identifiers in different systems.
+
+3. Random UUID's (UUIDv4) do not reveal information about object count
+   and rate of growth. Probably doesn't matter for issues in a bug
+   tracker, can be significant for users or orders in a online shop.
+
+4. Humans never try to type UUID's, they copy-paste them. For numbers,
+   humans tend to believe that they can type numbers. They can't, not
+   without typos.
+
+5. You can't run out of UUID's. You can't run out of int64 too, but
+   you can easily run out of int32.
+
+There are some downsides, sure, but they are minor:
+
+1. UUID's are bigger, which means somewhat bigger database index size
+   and slightly slower comparison. Usually, difference is neglectable.
+
+2. Some humans are scared by long 36-character strings.
+
+And yet, despite all these wonderful properties, again and again,
+server applications choose to use integers for pretty much
+everything. Debbugs, GitHub, GitLab, Gitea, Jira, ICQ (who
+remembers?), QuickBase (who knows?).
+
+Even SourceHut, daring to defy "modern web" design patterns, still
+chose to identify issues on the bug tracker with integers. Sad.
+
+Migrating existing system is usually way too painful and not worth it,
+but if you are creating something from scratch, please consider using
+UUID's and allowing client to pick them. Thank you for allowing me to
+stay offline for a bit longer.