Re: -s- LIKELY SPAM SGeneratorUUID added

anthony berglas <[email protected]> Wed, 2 Oct 2013 08:55:17 +1000
Newsgroups gmane.comp.java.orm.simpleorm
Message-ID <CA+_PZMcQHhZDxporZUfD3jFrDuJmRH0y=C7QKuY_=jXLxbZwJQ@mail.gmail.com> 
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Well done.  Sequences are indeed a bad way to go inter database.  But UUIDs
are ugly.

One nice alternative is to prefix the sequence with a short db name that
generated them.  Then you do not have the collision problem, and you have
legible keys.

Of course, do not introduce surrogate keys where good natural keys are
available.  An evil practice that has become very common.

Anthony


On Wed, Oct 2, 2013 at 2:43 AM, Franck Routier <[email protected]>wrote:

> Hi all,
>
> I just added a new SGeneratorMode and SGeneratorUUID.
> The purpose is to have a pk generated as a version 4 pseudo-random UUID.
> This can be convinient if your record instances don't have a natural
> primary key, and you want to move them from one database instance to
> another.
>
> With sequence, this can be cumbersome, especially if other records hold
> references to thoses sequences, as sequences tend to collide...
> UUID give you a unique id, independant of the database instance, at the
> price of a quite long primary key (32 to 36 characters, depending on wether
> you keep dashes in your key or not).
>
> This approach is used for example in OpenBravo ERP, and is now available
> in Simpleorm :-)
>
> Regards,
>
> Franck
>
>
>


-- 

Dr Anthony Berglas, [email protected]       Mobile: +61 4 4838 8874
Just because it is possible to push twigs along the ground with ones nose
does not necessarily mean that that is the best way to collect firewood.

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<div dir=3D"ltr">Well done. =A0Sequences are indeed a bad way to go inter d=
atabase. =A0But UUIDs are ugly.<div><br></div><div>One nice alternative is =
to prefix the sequence with a short db name that generated them. =A0Then yo=
u do not have the collision problem, and you have legible keys.</div>

<div><br></div><div>Of course, do not introduce surrogate keys where good n=
atural keys are available. =A0An evil practice that has become very common.=
</div><div><br></div><div>Anthony</div></div><div class=3D"gmail_extra"><br=
>

<br><div class=3D"gmail_quote">On Wed, Oct 2, 2013 at 2:43 AM, Franck Routi=
er <span dir=3D"ltr">&lt;<a href=3D"mailto:[email protected]" target=
=3D"_blank">[email protected]</a>&gt;</span> wrote:<br><blockquote c=
lass=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;=
padding-left:1ex">

Hi all,<br>
<br>
I just added a new SGeneratorMode and SGeneratorUUID.<br>
The purpose is to have a pk generated as a version 4 pseudo-random UUID.<br=
>
This can be convinient if your record instances don&#39;t have a natural pr=
imary key, and you want to move them from one database instance to another.=
<br>
<br>
With sequence, this can be cumbersome, especially if other records hold ref=
erences to thoses sequences, as sequences tend to collide...<br>
UUID give you a unique id, independant of the database instance, at the pri=
ce of a quite long primary key (32 to 36 characters, depending on wether yo=
u keep dashes in your key or not).<br>
<br>
This approach is used for example in OpenBravo ERP, and is now available in=
 Simpleorm :-)<br>
<br>
Regards,<br>
<br>
Franck<br>
<br>
<br>
</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br><p>
</p><p>Dr Anthony Berglas, <a href=3D"mailto:[email protected]" target=3D=
"_blank">[email protected]</a>=A0=A0=A0=A0=A0=A0 Mobile: +61 4 4838 8874<=
br>
Just because it is possible to push twigs along the ground with ones nose<b=
r>
does not necessarily mean that that is the best way to collect firewood.</p=
>
</div>




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