To return expected results, you can:
Reduce the number of search terms.
Each term you use focuses the search further.
Check your spelling.
A single misspelled or incorrectly typed term can change your result.
Try substituting synonyms for your original terms.
For example, instead of searching for "java classes", try "java training"
Did you search for an IBM acquired or sold product ?
If so, follow the appropriate link below to find the content you need.
IBM customers requested to backport JIRA OPENJPA-1376 defect to
WebSphere Application Server V6.1 (OpenJPA 1.0.x).
https://issues.apache.org/jira/browse/OPENJPA-1376
Local fix
Problem summary
****************************************************************
* USERS AFFECTED: All users of IBM WebSphere Application *
* Server V6.1.0 Feature Pack for Enterprise *
* JavaBeans 3.0 who make use of the *
* 'allocationSize' when using the *
* @SequenceGenerator annotation. *
****************************************************************
* PROBLEM DESCRIPTION: OpenJPA's implementation of the *
* allocationSize in a @SequenceGenerator *
* is incorrectly implemented. *
****************************************************************
* RECOMMENDATION: *
****************************************************************
The Javadoc for the 'allocationSize' property of the
@SequenceGenerator annotation defines the 'allocationSize' as
follows: "The amount to increment by when allocating sequence
numbers from the sequence." OpenJPA is using this value as a
caching value. That is, when generating a native sequence, an
SQL like the following my be generated:
CREATE SEQUENCE entityE2_seq_gen START WITH 1 INCREMENT BY 50
CACHE 50
In this SQL statement, OpenJPA is using a 'CACHE 50'
statement, where the value 50 is the allocationSize. By using
caching, OpenJPA is requesting a sequence value from the
database each time it needs a new sequence. The database is
in turning caching sequence values. This results in extra
calls to the database. A more efficient approach would be for
OpenJPA to cache the sequence value in memory, rather than
relying on the database, and thus honoring the true meaning of
'allocationSize'. Allocating values in memory allows the
OpenJPA runtime to avoid accessing the database for every
sequence request. That is, when 'allocationSize' is set to
50, OpenJPA will set aside the next 50 numbers each time it
accesses the sequence, which in turn means it only has to make
a database trip to get new sequence numbers once every 50
sequence number requests. In this case, a sequence similar to
the following should be generated:
CREATE SEQUENCE entityE2_seq_gen START WITH 1 INCREMENT BY 50
Problem conclusion
To enable the code of this fix, please use the
following JVM system property:
-Dopenjpa.jdbc.DBDictionary=useNativeSequenceCache=false
Or add the following to your persistence.xml file:
<property name="openjpa.jdbc.DBDictionary"
value="useNativeSequenceCache=false"/>
With this fix, and the above system property, OpenJPA will use
the 'allocationSize' as intended (i.e. as the increment when
allocation sequence numbers).
The fix for this APAR is currently targeted for inclusion
in Enterprise JavaBeans 3.0 Feature Pack Fix Pack 45
(6.1.0.45) of WebSphere Application Server version 6.1.
Please refer to the recommended updates page for delivery
information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Comments
APAR Information
APAR number
PM63898
Reported component name
WAS EJB3 FEATUR
Reported component ID
5724J0851
Reported release
610
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2012-05-03
Closed date
2012-05-21
Last modified date
2012-05-21
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fixed component name
WAS EJB3 FEATUR
Fixed component ID
5724J0851
Applicable component levels
R610 PSY
UP
[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Edition":"","Line of Business":{"code":"LOB45","label":"Automation"}}]
