Spring @Transactional read-only propagation

by

First of all, since Spring doesn’t do persistence itself, it cannot specify what readOnly should exactly mean. This attribute is only a hint to the provider, the behavior depends on, in this case, Hibernate.

If you specify readOnly as true, the flush mode will be set as FlushMode.NEVER in the current Hibernate Session preventing the session from committing the transaction.

Furthermore, setReadOnly(true) will be called on the JDBC Connection, which is also a hint to the underlying database. If your database supports it (most likely it does), this has basically the same effect as FlushMode.NEVER, but it’s stronger since you cannot even flush manually.

Now let’s see how transaction propagation works.

If you don’t explicitly set readOnly to true, you will have read/write transactions. Depending on the transaction attributes (like REQUIRES_NEW), sometimes your transaction is suspended at some point, a new one is started and eventually committed, and after that the first transaction is resumed.

OK, we’re almost there. Let’s see what brings readOnly into this scenario.

If a method in a read/write transaction calls a method that requires a readOnly transaction, the first one should be suspended, because otherwise a flush/commit would happen at the end of the second method.

Conversely, if you call a method from within a readOnly transaction that requires read/write, again, the first one will be suspended, since it cannot be flushed/committed, and the second method needs that.

In the readOnly-to-readOnly, and the read/write-to-read/write cases the outer transaction doesn’t need to be suspended (unless you specify propagation otherwise, obviously).

More Related Contents:

  1. @Transactional on @PostConstruct method
  2. Where should “@Transactional” be placed Service Layer or DAO
  3. The matching wildcard is strict, but no declaration can be found for element ‘tx:annotation-driven’
  4. Spring @Transactional with a transaction across multiple data sources
  5. why does transaction roll back on RuntimeException but not SQLException
  6. SPRING MVC getting 404 error in when you hits the submit button
  7. Spring @Autowire on Properties vs Constructor
  8. Why does self-invocation not work for Spring proxies (e.g. with AOP)?
  9. Spring Resttemplate exception handling
  10. How to do conditional auto-wiring in Spring?
  11. Why does Hibernate disable INSERT batching when using an IDENTITY identifier generator
  12. Environment Specific application.properties file in Spring Boot application [closed]
  13. How do I send spring csrf token from Postman rest client?
  14. List as form backing object using Spring 3 MVC, correct syntax?
  15. Spring CSRF token does not work, when the request to be sent is a multipart request
  16. Spring catch all route for index.html
  17. Transactional annotation avoids services being mocked
  18. Handling ambiguous handler methods mapped in REST application with Spring
  19. How to call a method after bean initialization is complete?
  20. How to use LocalDateTime RequestParam in Spring? I get “Failed to convert String to LocalDateTime”
  21. User Defined Type with spring-data-cassandra
  22. Spring REST using Jackson – 400 bad request logging
  23. Injection of autowired dependencies failed;
  24. Customized ObjectMapper not used in test
  25. Reloading/Refreshing Spring configuration file without restarting the servlet container
  26. Create Account, Forgot Password and Change Password
  27. Spring Social Authentication Filter for Stateless REST Endpoints which use Facebook Token for authentication
  28. Spring Batch: Reading fixed-width file without line breaks
  29. CSS not loading in Spring Boot
  30. Adding custom RequestCondition’s in Spring mvc 3.1

Leave a Comment