Spring boot jpa identity, ids of new rows jumped forward by 10K

Question

I'm using spring boot JPA 2.1.18.
All my model classes derives from this base class:

@Getter
@Setter
@MappedSuperclass
@EntityListeners(AuditingEntityListener.class) 
public abstract class DbEntity {

   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   protected Long id;

   ....
}

Everything works fine, but I'm facing a strange behaviour with the ids used for the new rows in the db ( I'm using SqlServer):

As you casn see, suddenly the ids jumped forward by 10000 and I don't understand why (it's impossible that the java code reserves 10000 ids, because I don't have batch processes). Any suggestions?

Answer 1

This is because of an option in SQL Server called IDENTITY_CACHE, take a look at this page from Microsoft which explains a bit more

https://learn.microsoft.com/en-us/sql/t-sql/statements/alter-database-scoped-configuration-transact-sql?view=sql-server-ver15

To disable it, run the below under your database

USE DatabaseName
GO
ALTER DATABASE SCOPED CONFIGURATION SET IDENTITY_CACHE = OFF
GO

Note that this can have a performance penalty