How To Generate Sequences Of Identifiers Via Hibernate pooled-lo Algorithm

Note: Rely on pooled-lo or pooled especially if, beside your application, external systems needs to insert rows in your tables. Don't rely on hi/lo since, in such cases, it may cause errors resulted from generating duplicated identifiers.

Description: This is a Spring Boot example of using the pooled-lo algorithm. The pooled-lo is an optimization of hi/lo similar with pooled. Only that, the strategy of this algorithm fetches from the database the current sequence value and use it as the in-memory lowest boundary identifier. The number of in-memory generated identifiers is equal to increment_size.

Key points:

• use the SEQUENCE generator type (e.g., in PostgreSQL)
• configure the pooled-lo algorithm as in Author.java entity
• insert a few records via pooled-lo
• insert a few records natively (this acts as an external system that relies on NEXTVAL('hilo_sequence') and is not aware of pooled-lo presence and/or behavior)

---

If you need a deep dive into the performance recipes exposed in this repository then I am sure that you will love my book "Spring Boot Persistence Best Practices"	If you need a hand of tips and illustrations of 100+ Java persistence performance issues then "Java Persistence Performance Illustrated Guide" is for you.

---