quarkusio/quarkus · error · UnsupportedOperationException

This isn't used for schema generation - see SessionFactoryOb

Error message

This isn't used for schema generation - see SessionFactoryObserverForSchemaExport instead

What it means

FastBootEntityManagerFactoryBuilder replaces Hibernate's normal EMF bootstrap in Quarkus; schema generation is not driven through the standard EntityManagerFactoryBuilder.generateSchema path. Instead Quarkus performs schema export via SessionFactoryObserverForSchemaExport, so calling generateSchema directly is an explicit UnsupportedOperationException.

Source

Thrown at extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/boot/FastBootEntityManagerFactoryBuilder.java:108

            populate(puDescriptor.getName(), optionsBuilder, standardServiceRegistry);
            return new SessionFactoryImpl(metadata, optionsBuilder.buildOptions(),
                    metadata.getTypeConfiguration().getMetadataBuildingContext().getBootstrapContext());
        } catch (Exception e) {
            throw persistenceException("Unable to build Hibernate SessionFactory", e);
        } finally {
            closeImportScripts();
        }
    }

    @Override
    public void cancel() {
        // nothing?
    }

    @Override
    public void generateSchema() {
        try {
            throw new UnsupportedOperationException(
                    "This isn't used for schema generation - see SessionFactoryObserverForSchemaExport instead");
        } finally {
            closeImportScripts();
        }
    }

    protected final void closeImportScripts() {
        importScripts.close();
    }

    protected PersistenceException persistenceException(String message, Exception cause) {
        // Provide a comprehensible message if there is an issue with SSL support
        Throwable t = cause;
        while (t != null) {
            if (t instanceof NoSuchAlgorithmException) {
                message += "Unable to enable SSL support. You might be in the case where you used the `quarkus.ssl.native=false` configuration"
                        + " and SSL was not disabled automatically for your driver.";
                break;

View on GitHub (pinned to e1c734241f)

Solutions

1. Let Quarkus handle schema generation via configuration: quarkus.hibernate-orm.database.generation=(create|drop-and-create|update).
2. Use Hibernate SchemaExport/SchemaUpdate tooling explicitly if you need manual control.
3. Register schema work through a SessionFactoryObserverForSchemaExport-compatible mechanism instead of the JPA bootstrap API.

Example fix

// before
emfBuilder.generateSchema();
// after
// application.properties
quarkus.hibernate-orm.database.generation=drop-and-create

// Guard custom tooling before invoking generateSchema
if (emfBuilder instanceof FastBootEntityManagerFactoryBuilder) {
    throw new IllegalStateException("Use quarkus.hibernate-orm.database.generation instead");
}

try {
    builder.generateSchema();
} catch (UnsupportedOperationException e) {
    log.warn("Schema generation handled by Quarkus config; set "
        + "quarkus.hibernate-orm.database.generation instead");
}

When it happens

Trigger: Calling EMFBuilder.generateSchema() (or Persistence.generateSchema / javax.persistence.schema-generation via the raw EMF) on Quarkus's fast-boot EMF — e.g. custom tooling invoking JPA schema generation APIs at runtime.

Common situations: Porting standard Hibernate/JPA code that calls generateSchema into a Quarkus app; running a schema tool harness expecting the JPA bootstrap contract.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• This method is not available at runtime in Quarkus
• Stateless operations not supported
• Cannot find ORM mapping file '${mappingFileName}' in the cla
• Missing attribute '${nodeName}.class'
• Annotation ${dotName} was not expected on a target of kind $

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/ad0728b6b189ea94. Report an issue: GitHub.