JPA-based event publications created by JPA provider using wrong column definition in PostgreSQL

[kalwinskidawid]

Hey @odrotbohm, I found a strange aberration. I created a simple application with JPA + PostgreSQL, I let JPA create the schema (I know, I know you recommend creating it yourself). However, documentation says that the columns should be TEXT, but when JPA initializes the default schema, it defines a varchar(255), which is quite small for serialized_event.

Definition from documentation:

CREATE TABLE IF NOT EXISTS event_publication
(
  id               UUID NOT NULL,
  listener_id      TEXT NOT NULL,
  event_type       TEXT NOT NULL,
  serialized_event TEXT NOT NULL,
  publication_date TIMESTAMP WITH TIME ZONE NOT NULL,
  completion_date  TIMESTAMP WITH TIME ZONE,
  PRIMARY KEY (id)
);
CREATE INDEX IF NOT EXISTS event_publication_serialized_event_hash_idx ON event_publication USING hash(serialized_event);
CREATE INDEX IF NOT EXISTS event_publication_by_completion_date_idx ON event_publication (completion_date);

Is the documentation outdated, or is something wrong with the spring-modulith-starter-jpa package ?

[odrotbohm]

That's precisely why we don't recommend letting the JPA provider create the database schema in the first place. As you can see from the different schemas we have listed for the JDBC-based implementation, the column type for the serialized event varies from database to database. The translation from the JPA entity to the database column is entirely in the hands of the JPA provider, and the JPA annotations don't allow us to express “use whatever text column type is appropriate for the database vendor you're running on”.

We generally recommend to simply stick with the JDBC-based event publication registry implementation, even for JPA deployments, as the database interactions required for the publication management does not really benefit from JPA. It should be a slight bit faster even.

So I don't think we have anything actionable here, as the documentation is indeed correct, talking about the schemas used for the JDBC-based registry (opening of the first sentence).

[kalwinskidawid]

So it comes out that org.springframework.modulith:spring-modulith-starter-jpa is useless?

I moved to org.springframework.modulith:spring-modulith-starter-jdbc as you said and everything works fine, thanks.