What database were you using? For example with SQL server, by default it clusters data on disk by primary key. Random (non-sequential) PKs like uuidv4 require random cluster shuffling to insert a row “in the middle” of a cluster, increasing io load and causing performance issues.
Postgres on the other hand doesn’t do clustered indexing on the PK… if I recall correctly.
Postgres is not immune to uuid issues, just less sensitive, uuidv4 still does not play well with btree indexes, bloating them and impacting their performance.
Postgres on the other hand doesn’t do clustered indexing on the PK… if I recall correctly.