Large Objects may not be used in auto-commit mode

Question

I have a Spring application which uses Hibernate on a PostgreSQL database. I\'m trying to store files in a table of the database. It seems it stores the row with the file (I

Answer 1

A large object can be stored in several records, that's why you have to use a transaction. All records are correct or nothing at all.

https://www.postgresql.org/docs/current/static/largeobjects.html

Answer 2

Instead of using @Transactional, all I did for this issue was to update this column in PostgreSQL DB from oid type to bytea type and added @Type for the @Lob field.

i.e.

ALTER TABLE person DROP COLUMN image;
ALTER TABLE person ADD COLUMN image bytea;

And changed

@Lob
private byte[] image;

To

@Lob
@Type(type = "org.hibernate.type.ImageType")
private byte[] image;

Answer 3

Use @Transactional on your Repository Interface.

Answer 4

You should check if auto-commit is really set false with method getAutoCommit() on your Connection.

In my case

<property name="hibernate.connection.autocommit" value="false" />

did not work, because the type of my db connection required auto-commit to be true.

In my case the problem was in the JBoss Configuration. I was using an JTA-datasource and that caused the problem. With an XA-datasource it worked fine. See this post for more details.

Answer 5

If you can, create a intermediate Entity between MyClass and file property for instance. Something like:

@Entity
@Table(name="myobjects")
public class MyClass {
    @OneToOne(cascade = ALL, fetch = LAZY)
    private File file;
}

@Entity
@Table(name="file")
public class File {
     @Lob
     byte[] file;
}

You can't use @Lob and fetch type Lazy. It doesnt work. You must have a a intermediate class.

Answer 6

Unless you need to store files large than 1GB I suggest you use bytea as the datatype instead of large object.

bytea is basically what BLOB is in other databases (e.g. Oracle) and it's handling is a lot more compatible with JDBC.