[hibernate-dev] HHH-6726 LONG and LONG RAW column types in Oracle

[Łukasz Antoniak]

Welcome Community!

I have just subscribed to the list and wanted to discuss HHH-6726 JIRA 
issue.

Gail Badner wrote 
(http://lists.jboss.org/pipermail/hibernate-dev/2011-October/007208.html):
HHH-6726 (Oracle : map TextType to clob and ImageType to blob)
https://hibernate.onjira.com/browse/HHH-6726
There have been a number of issues opened since the change was made to 
map TextType (LONGVARCHAR) 'long' and ImageType (LONGVARBINARY) to 'long 
raw'. This change was already documented in the migration notes. Should 
the mapping for Oracle (only) be changed back to clob and blob?

HHH-6726 is caused by an issue in Oracle JDBC driver (version 10.2.0.4 
and later). This bug appears when LONG or LONG RAW columns are accessed 
not as first or last while processing SQL statement.

I have discussed the topic of mapping TextType to CLOB and ImageType to 
BLOB (only in Oracle dialect) with Strong Liu. Reasons for doing so:
- Oracle allows only one LONG / LONG RAW column per table. This might be 
the most important from Hibernate's perspective.
- LONG / LONG RAW - up to 2 GB, BLOB / CLOB - up to 4 GB.
- In PL/SQL using LOBs is more efficient (random access to data). LONG 
only sequential.
- LONG and LONG RAW are deprecated.

What is your opinion?

Regards,
Lukasz Antoniak