一意のインデックスキーを生成する場合にこの設定は有効に

https://access.redhat.com/documentation/ja-JP/JBoss_Enterprise_Application_Platform/6/html/Migration_Guide/Hibernate_JPA_Persistence_Unit_Properties.html

Hilo algorithm

Hibernate will do a next value call on sequence
and then calculate the values he will use from memory with the following formula
(e.g. allocationSize is 50 and current sequence value is 5):

upperLimit = (5 * 50) + 1 = 251
lowerLimit = (251 - 50) = 201.

Hiloの関連エラー

https://hibernate.atlassian.net/browse/HHH-10656

sequenceを stringで保存する場合や prefixをつけて利用する場合

http://stackoverflow.com/questions/12517421/how-to-map-a-string-to-db-sequence-in-hibernate

References

• Sequences in Hibernate
• 3.2.2.3. Hibernate JPA 永続ユニットプロパティ