Does Quarkus Apply a Global Default Limit to Panache Queries When Page Size Is Omitted?

No Global Default Limit

Quarkus Hibernate Panache does not apply a global default limit to queries when a page size is omitted. If you execute a query using .list() or .stream() without explicitly providing a Page object or a limit parameter, Panache retrieves all matching records from the database.

Behavior Across Stacks

This behavior is uniform across both the RESTEasy Reactive and Vert.x reactive stacks. Because Panache acts as a layer over Hibernate ORM, it adheres to standard JPA behavior: a SELECT query without a defined limit is translated into SQL that requests the entire result set. Neither the reactive engine nor the REST layer injects a hidden default limit to protect the application from large datasets.

Risk of Unbounded Queries

Because there is no global safety limit, omitting pagination on large tables can lead to OutOfMemoryError (OOM) as the JVM attempts to load the entire result set into the heap. This is particularly critical in reactive stacks where blocking the event loop with massive data processing can degrade system performance.

Verification Steps

To verify the absence of a default limit in your specific environment, follow these steps:

1. Enable SQL logging in your application.properties:

   quarkus.hibernate-orm.log.sql=true

2. Execute a Panache query (e.g., repository.listAll()) against a table containing more than 1,000 records.
3. Inspect the console output. If no LIMIT or TOP clause appears in the generated SQL, the query is unbounded.
4. Check the size of the returned list to confirm it matches the total record count in the database.

Diagnostic Note: If you are seeing truncated results despite not setting a limit, please specify if you are using a custom QueryInterceptor or a specific database proxy (such as a cloud-managed SQL gateway) that may be enforcing limits outside of the Quarkus application.