Hi,

I am trying to insert a Blob into an oracle database using Hibernate. I am using the approach mentioned at http://hansonchar.blogspot.com/2005/06/oracle-blob-mapped-to-byte-in.html

i.e. converting the BLOB to a byte array.

The problem is the application runs fine when i update a single record. If i try to run the application and update 2 records, Hibernate just hangs at the point where session.getTransaction().commit() gets invoked, so the commit is never invoked.
Any idea what could be the problem?

Any help would be appreciated.

Thanks in advance.

this is happening to me as well. though, it doesn't happen all the time. there are instances when i can upload 2 - 3 files at a time w/ no problem. also, i know that size is not the issue b/c i've had success with +2Mb files and it's failed in cases where the files that total <1Mb. when the update hangs, it also locks the record since the transaction was never committed so i end up having to restart my app server to get the record released.

Hibernate version: 3.2.2.ga
Database: Oracle 9i

I found a work around for the problem. I found that if i commit the session after inovking session.save() for each record it works fine. Earlier i had a single session object ans used it in a for loop to update each record. Now, i commit the session after saving each record and create a new session in the for loop. I dont think this is a very good solution i.e. creating a new session for each row in the loop. Is there any other workaround?

Try to do just flush and clear instead of commit, like in batch processing

http://www.hibernate.org/hib_docs/v3/re ... batch.html

Maybe this will work also?

Regards,
Pavol

Today when i executed the application even after creatign session in the for loop the problem still occurred. And session.flush() also doesnt work, if i put it, code hangs at the point where session.flush() is invoked. Any idea how i can work around this issue?

Any help would be greatly appreciated, I'm really stuck with this problem.

Thanks in advance.

Can you catch the stack where it hangs?

code hangs at the point where session.commit() gets executed so this line is never executed. My log file shows the following as its last statement:

DEBUG org.hibernate.jdbc.AbstractBatcher - Executing batch size: 2

There is no exception printed.

Does it make sense?

Can you connect with jconsole for example and look the exact stack trace where it hangs?

I was having the exact same problem as parallax555 -- updating multiple BLOBs in a single transaction would hang. In addition, our DBAs were watching the database during the "hang" and Oracle didn't show blocking locks or any signs of distress. The final log statement displayed was:
DEBUG org.hibernate.jdbc.AbstractBatcher - Executing batch size: 2

We are using the Oracle 10.2.0.2.0 JDBC driver, Hibernate 3.0.5, and Oracle 9 database.

Becuase the last logging line was regarding batching, I tried disabling JDBC batching by adding this line to my hibernate.cfg.xml:
<property name="hibernate.jdbc.batch_size">0</property>

Now it works flawlessly! I've inserted up to 10 BLOBs in a single transaction without hanging.

I hope this helps!

Regards,
Tara