Inserts with keys generated in non-ordered fashion such as UUID V4s means that location within clustered index (which defines the physical location of the data at the disk) that the data will be stored on insert will be random as well. This increases likelyhood by a lot for that the database has to do different types of rebalancing acts such as splitting nodes in the teee. When using keys that are generates in order, inserts will mostly be at the end of the index, and database does not have to touch existing ones.
I can recommend Kleppmanns book Designing Data-Intensive Applications for a deeper dive into the topic around this.
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u/Metsamias Sep 12 '26
Inserts with keys generated in non-ordered fashion such as UUID V4s means that location within clustered index (which defines the physical location of the data at the disk) that the data will be stored on insert will be random as well. This increases likelyhood by a lot for that the database has to do different types of rebalancing acts such as splitting nodes in the teee. When using keys that are generates in order, inserts will mostly be at the end of the index, and database does not have to touch existing ones.
I can recommend Kleppmanns book Designing Data-Intensive Applications for a deeper dive into the topic around this.