#uuidv7

Random UUIDv4 primary keys slowed our inserts 6x; switching to UUIDv7 fixed it

Insert throughput on our events table fell by a factor of six as it passed 400 million rows, while CPU stayed idle. The cause was random UUIDv4 keys scattering writes across the whole primary key index. Postgres 18 uuidv7() brought it back, without changing the column type.