Hello John,
you misunderstood.
The Sequence is defined as follows:
CREATE SEQUENCE MY.OID_SEQ AS BIGINT
START WITH 100000
INCREMENT BY 1000
CYCLE
CACHE 10;
We were using identity columns earlier but switched to dedicated sequences to
benefit from the ability to cache numerous ID values in advance to reduce
database accesses.
Tobias
-----Original Message-----
From: Boblitz John [mailto:john.bobl...@bertschi.com]
Sent: Donnerstag, 17. Oktober 2013 16:43
To: 'users@openjpa.apache.org'
Subject: RE: How to avoid ALTER SEQUENCE statement?
Hello Tobias,
maybe I misunderstand, but is your sequence defined in the DB Table itself?
If it is, I think your need to use the GenerationType.IDENTITY -
if not, please disregard.
Cheers,
John
> -----Original Message-----
> From: Meyer, Tobias [mailto:tobias.me...@capgemini.com]
> Sent: Thursday, October 17, 2013 3:54 PM
> To: users@openjpa.apache.org
> Subject: How to avoid ALTER SEQUENCE statement?
>
> Hi,
>
> we’re using OpenJPA 2.2.2 in WebSphere 8.5 and are faced with the following
> problem with the way OpenJPA handles native sequences.
>
> Our Entities have IDs defined like this:
> @Id
> @SequenceGenerator(name = "MY_OID_SEQ", schema = "MY", sequenceName
> = "OID_SEQ", allocationSize = 1000) @GeneratedValue(strategy =
> GenerationType.SEQUENCE, generator = "MY_OID_SEQ") @Column(name =
> "OID") private long oid;
>
> OpenJPA’s NativeJDBCSeq class seems to have no trust in the developers using
> native sequences and issues an “ALTER SEQUENCE MY.OID_SEQ INCREMENT
> BY 1000” statement the first time an object gets persisted/inserted.
> This happens regardless of the fact that the sequence is already correctly
> defined.
>
> Now the problem is that (of course) the application doesn’t have the rights to
> alter neither tables nor sequences, so the statement fails and the transaction
> rolls back (i.e. our object will not be persisted).
> AND OpenJPA disables the caching of IDs completely resulting in massive
> performance issues when persisting large amounts of objects.
>
> 1. Giving the application the right to alter sequences is not an option, so
> how
> can we avoid that OpenJPA issues the ALTER SEQUENCE statement???
> 2. For further releases: PLEASE enable the developer to disable this easily,
> by
> setting a configuration value or something like that. And don’t issue an ALTER
> SEQUENCE statement if the sequence doesn’t need to be altered!
>
> Thanks for your help,
> Tobias
>
>
> ________________________________________________________________
> _______
> Tobias Meyer
> Custom Solution Development | Application Services
>
> Capgemini | Hamburg
> Phone: +4940254491291 – Mobile: +4915140250554
> e-mail: tobias.me...@capgemini.com
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>
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This message contains information that may be privileged or confidential and is
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