Re: [hibernate-dev] HHH-6726 LONG and LONG RAW column types in Oracle
by Łukasz Antoniak
Currently Oracle supports database versions from 10.1 to 11.2 [1]. LONG
and LONG RAW data types are deprecated since version 8 and 8i (released
before September 2000) [2]. Oracle keeps those column types only for
backward compatibility [3].
I tried the following scenario (Oracle 10gR2):
1. Create schema with "hibernate.hbm2ddl.auto" set to "create". The LONG
column is created.
2. Insert some data.
3. Modify Oracle dialect as Gail suggested. Avoid setting
"hibernate.hbm2ddl.auto".
4. Insert some data.
To my surprise the test actually passed :). However, I think that we
cannot guaranty the proper behavior in every situation.
As for performance, ImageType is extracted by calling
ResultSet.getBytes() method, which fetches all data in one call [4]. I
don't suppose a major performance difference when data is streamed in
another call. oracle.jdbc.driver.LongRawAccessor.getBytes also fetches
data by reading the stream.
The bug reading LONG column affects JDBC drivers since version 10.2.0.4.
I think that we have to choose between:
- changing Oracle10gDialect. Make a not about it in migration guide to
4.0 and update "5.2.2. Basic value types" chapter in Hibernate
documentation.
- introducing Oracle11gDialect. It can sound weird to access Oracle 10g
database with Oracle 11g dialect.
- disabling execution of Hibernate tests that fail because of this issue
with @SkipForDialect (and maybe develop another version of them with
CLOBs and BLOBs, @RequiresDialect). Hibernate is written correctly
according to "Default Mappings Between SQL Types and Java Types"
(referenced earlier by Gail) and this is more Oracle's JDBC
implementation issue. This option came to my mind, but it's weird :P.
I would vote for the first option.
Regards,
Lukasz Antoniak
[1]
http://www.oracle.com/us/support/library/lifetime-support-technology-0691...
(page 4)
[2]
http://download.oracle.com/docs/cd/A91202_01/901_doc/server.901/a90120/ch...
[3]
http://download.oracle.com/docs/cd/B28359_01/server.111/b28318/datatype.htm
[4] "Getting a LONG RAW Data Column with getBytes"
http://download.oracle.com/docs/cd/B19306_01/java.102/b14355/jstreams.htm
Strong Liu pisze:
> I think oracle 11g is the only one supported DB version by oracle, can we just introduce a new oracle dialect with suggested changes, and deprecate all other existed oracle dialects? this won't affects users app
>
> -----------
> Strong Liu <stliu(a)hibernate.org>
> http://hibernate.org
> http://github.com/stliu
>
> On Oct 15, 2011, at 11:14 AM, Scott Marlow wrote:
>
>> How does this impact existing applications? Would they have to convert
>> LONGs to CLOBs (and LONGRAWs to BLOBs) to keep the application working?
>>
>> As far as the advantage of CLOB over TEXT, if you read every character,
>> which one is really faster? I would expect TEXT to be a little faster,
>> since the server side will send the characters before they are asked
>> for. By faster, I mean from the application performance point of view. :)
>>
>> Could this be changed in a custom Oracle dialect? So new
>> applications/databases could perhaps use that and existing applications
>> might use LONGs a bit longer via the existing Oracle dialect.
>>
>> On 10/14/2011 09:22 PM, Gail Badner wrote:
>>> In [1], I am seeing the following type mappings:
>>>
>>> Column type: LONG -> java.sql.Types.LONGVARCHAR -> java.lang.String
>>> Column type: LONGRAW -> java.sql.Types.LONGVARBINARY -> byte[]
>>>
>>> org.hibernate.type.TextType is consistent with the mapping for LONG.
>>>
>>> org.hibernate.type.ImageType is consistent with the mapping for LONGRAW.
>>>
>>> From this standpoint, the current settings are appropriate.
>>>
>>> I understand there are restrictions when LONG and LONGRAW are used and I see from your other message that there is Oracle documentation for migrating to CLOB and BLOB.
>>>
>>> I agree that changing column type registration as follows (for Oracle only) should fix this:
>>> registerColumnType( Types.VARBINARY, 2000, "raw($l)" );
>>> registerColumnType( Types.VARBINARY, "blob" );
>>>
>>> registerColumnType( Types.LONGVARCHAR, "clob" );
>>> registerColumnType( Types.LONGVARBINARY, "blob" );
>>>
>>> registerColumnType( Types.VARCHAR, 4000, "varchar2($l char)" );
>>> registerColumnType( Types.VARCHAR, "clob" );
>>>
>>> Steve, what do you think? Is it too late to make this change for 4.0.0?
>>>
>>> [1] Table 11-1 of Oracle® Database JDBC Developer's Guide and Reference, 11g Release 1 (11.1) (http://download.oracle.com/docs/cd/B28359_01/java.111/b31224/datacc.htm#g...)
>>> [2] Hibernate Core Migration Guide for 3.5 (http://community.jboss.org/wiki/HibernateCoreMigrationGuide35)
>>> [3] Table 2-10 of Oracle® Database SQL Language Reference
>>> 11g Release 1 (11.1) (http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/sql_elemen...)
>>>
>>> ----- Original Message -----
>>>> From: "Łukasz Antoniak"<lukasz.antoniak(a)gmail.com>
>>>> To: hibernate-dev(a)lists.jboss.org
>>>> Sent: Thursday, October 13, 2011 12:50:13 PM
>>>> Subject: [hibernate-dev] HHH-6726 LONG and LONG RAW column types in Oracle
>>>>
>>>> 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
>>>> _______________________________________________
>>>> hibernate-dev mailing list
>>>> hibernate-dev(a)lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>>>>
>>> _______________________________________________
>>> hibernate-dev mailing list
>>> hibernate-dev(a)lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>> _______________________________________________
>> hibernate-dev mailing list
>> hibernate-dev(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>
8 years, 10 months
Changelog file in Hibernate ORM
by Sanne Grinovero
The file changelog.txt in the root ot the Hibernate ORM project seems outdated.
Is it not maintained anymore? I found it handy.
Sanne
9 years, 6 months
Re: [hibernate-dev] Search - HSEARCH-1580 - Dependency graph
by Guillaume Smet
Hi Hardy,
Thanks for your feedback. I'll see what I can do next week about it.
--
Guillaume
On Fri, Jul 25, 2014 at 9:12 PM, Hardy Ferentschik <hardy(a)hibernate.org> wrote:
> Hi,
>
> took a while to respond, but I tend to agree that @ContainedIn would be good enough.
> I don’t think a new annotation would make things clearer. As discussed before, the main
> issue was that the original intention was that @ContainedIn always requires an @IndexedEmbedded.
> It just happened to work also without and during the refactoring the behaviour was changed to
> match the original intentions.
>
> The important thing is to make sure that the documentation and javadocs are documenting the
> behaviour properly and consistently.
>
> So +1 for getting the old behaviour back
>
> —Hardy
>
>
>
>
>
> On 20 Jan 2014, at 11:08, Guillaume Smet <guillaume.smet(a)hibernate.org> wrote:
>
>> Hi,
>>
>> Following the discussion about releasing 5 sooner rather than later, I
>> wanted to point out that we still have to take a decision about
>> HSEARCH-1580:
>> - either commit in 5 the fix we committed to 4.x and update the documentation;
>> - or work on defining another concept.
>>
>> I don't have a strong opinion about what we should do but I have a
>> strong one about doing something before we release 5 :).
>>
>> References:
>> https://hibernate.atlassian.net/browse/HSEARCH-1580
>> https://hibernate.atlassian.net/browse/HSEARCH-1573
>>
>> Feedback welcome.
>>
>> (sorry for the long silence - busy months...)
>>
>> --
>> Guillaume
>> _______________________________________________
>> hibernate-dev mailing list
>> hibernate-dev(a)lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/hibernate-dev
>
10 years
Signing up for JIRA
by Gunnar Morling
Hi,
In JIRA I'm seeing this permanent message:
"Need to file a bug report and don't have an account? Email emmanuel at
hibernate dot org with JIRA Account creation as subject. You'll receive an
invite by email."
So have we abandoned the self sign-up? Why is this, due to spamming issues?
Not sure whether it's really a problem, but this may raise the barrier for
getting a JIRA account and thus stop some new users from reporting bugs.
--Gunnar
10 years, 1 month
Contributing to OGM / Cassandra
by John Worrell
Hi,
I'm interested in contributing to the Cassandra module of Hibernate-OGM -
what would be the baest way to go about this?
Thanks,
John
10 years, 2 months
Gradle not running some unit tests
by Etienne Miret
Hello all,
Willing to investigate some Hibernate bugs, I downloaded the sources (from github), compiled them and ran unit tests. I used the provided Gradle wrapper to compile and run the tests. However, hibernate-core/target/reports/tests/index.html reports a number of test classes as not containing any tests. I mainly looked at org.hibernate.test.cut.CompositeUserTypeTest, and I can tell that:
* it contains two method annotated with @org.junit.Test
* it extends org.hibernate.testing.junit4.BaseUnitTestCase
(through BaseCoreFunctionalTestCase), which has a
@org.junit.runner.RunWith annotation.
>From what I know of Gradle, this is enough to have the tests detected and ran. And actually, those tests *are* detected and ran on branch 4.2. But on branch master, this test class appears in the report with 0 tests within.
Does anyone know why those tests are missing from the report?
In case this is of any help, here is the output of ./gradle --version:
------------------------------------------------------------
Gradle 1.9
------------------------------------------------------------
Build time: 2013-11-19 08:20:02 UTC
Build number: none
Revision: 7970ec3503b4f5767ee1c1c69f8b4186c4763e3d
Groovy: 1.8.6
Ant: Apache Ant(TM) version 1.9.2 compiled on July 8 2013
Ivy: 2.2.0
JVM: 1.7.0_60 (Oracle Corporation 24.60-b09)
OS: Mac OS X 10.9.4 x86_64
Regards,
--
Etienne Miret
10 years, 3 months
Exposing Hibernate statistics via JMX
by Gunnar Morling
Steve, all,
I've been asked about the Hibernate statistics functionality which used to
be accessible via JMX.
There used to be StatisticsService which was an MBean and which one could
register with the JMX platform. This has been removed a while ago, and
there is the related issue HHH-6190 which still is open.
Until this is resolved, what is the recommended strategy towards making the
statistics available via JMX? Should users create and export their own
MBean based on SessionFactory#getStatistics()? Or is there any other
replacement for StatisticsService?
Thanks,
--Gunnar
[1] https://hibernate.atlassian.net/browse/HHH-6190
10 years, 3 months
JdbcSession proposal
by Steve Ebersole
I found a few spare minutes to work on this a little and move it into
the next stage with some actual interfaces, impls and usages to help
illustrate some of the proposed concepts.
https://github.com/sebersole/JdbcSession
The README.md is very up-to-date and detailed. Would be good to get
input from others.
P.S. I probably dislike the *Inflow naming more than you do :)
10 years, 3 months
