Hi,
----- Original Message -----
From: "Farnea Massimiliano" <[EMAIL PROTECTED]>
To: "ojb-user" <[EMAIL PROTECTED]>
Sent: Monday, September 29, 2003 6:10 PM
Subject: Questions: High/Low Sequence Manager

> Hi all,
>
> I'm using in my application two implementation (extension) of the
> SequenceManagerHighLowImpl, one for managing primary keys and the last
for
> generating an application protocol number sequence. I've choosen the
> SequenceManagerHighLowImpl because I might have more than a JVM
pointing the
> same db. I have a couple of questions:
> 1. I can't understand the meaning of the grabSize parameter, can I set
it to
> '1' (the protocol number sequence have to be continous) ? Any
concurrency
> issues?
It's not granteed that the generated sequence keys are continuous.
If e.g. an store fails, obtained keys are lost (2,3,4,5,8,9...). But
they are unique.
The 'grabSize' attribute specify the number of keys ask for
from an intern DB-table (OJB_HL_SEQ).
See
http://db.apache.org/ojb/sequencemanager.html#High/Low sequence manager
and have a look in the source code.

> 2. The sequence-name for my implementations are diffent, one is
referenced
> only in the repository.xml, while I got direct access to the second in
my
> application code.
Sorry, I don't understand that.
Can you explain more.

regards,
Armin

> Are there any problems/advices in using two database
> driver sequence manager on the same db.
> Thanks in advance for your suggestions.
>
> Massimiliano Farnea
>
>
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