cayenne-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mike Kienenberger <mkien...@gmail.com>
Subject Re: Duplicate primary keys in Postgresql
Date Tue, 13 Oct 2015 19:14:11 GMT
Modifications to documentation can certainly be submitted as a pull request.
Thanks.

I'm not sure if what you've suggested about JdbcPkGenerator is possible.

On Tue, Oct 13, 2015 at 2:59 PM, Hugi Thordarson <hugi@karlmenn.is> wrote:
> Well, it could be documented in the article on primary key generation ("for performance
reasons, Cayenne doesn't ask the DB for a new primary key every time a record is inserted,
but fetches primary keys in batches etc.…”). I’ll write something up for the documentation
and submit it. Shouldn’t modifications to documentation be submitted as a pull request like
everything else?
>
> But even better would be if JdbcPkGenerator would warn the user if a DB generated PK
doesn’t match what it expects once the PK cache has been exhausted.
>
> Cheers,
> - hugi
>
>
>
>> On 13. okt. 2015, at 14:04, Mike Kienenberger <mkienenb@gmail.com> wrote:
>>
>> I remember that happening to me way back in Cayenne 1.x when I
>> converted over from EOF.    I wonder if there's any way we can make
>> this more obvious to the end-user who migrates from EOF?  Hugi, was
>> there any particular place where we could have documented this where
>> it would have become obvious to you during the migration?
>>
>> On Tue, Oct 13, 2015 at 9:55 AM, Hugi Thordarson <hugi@karlmenn.is> wrote:
>>> Thanks Michael, that was it. The sequences I was using were leftorvers from EOF
and were advancing by 1 at a time, while Cayenne expected 20. Now everything works like a
charm :).
>>>
>>> Cheers,
>>> - hugi
>>>
>>>
>>>
>>>> On 13. okt. 2015, at 13:36, Michael Gentry <mgentry@masslight.net>
wrote:
>>>>
>>>> Hi Hugi,
>>>>
>>>> What are you using for PK generation?  PostgreSQL's sequence generator
>>>> should prevent duplicates.  Make sure the number of keys it is allocating
>>>> matches what Cayenne is using, though, otherwise you'll run into issues.
>>>>
>>>> mrg
>>>>
>>>>
>>>> On Tue, Oct 13, 2015 at 5:38 AM, Hugi Thordarson <hugi@karlmenn.is>
wrote:
>>>>
>>>>> Hi again all!
>>>>>
>>>>> I’m running into a problem where I’m getting duplicate primary keys
in
>>>>> Postgresql, i.e. records are getting the same primary key (when multiple
>>>>> threads are writing to the same table). Any idea how I can prevent this?
Do
>>>>> I have to perform any manual synchronization?
>>>>>
>>>>> Cheers,
>>>>> - hugi
>>>>>
>>>>> // Hugi Thordarson
>>>>> // http://www.loftfar.is/
>>>>> // s. 895-6688
>>>>>
>>>
>

Mime
View raw message