Re: "ownership" of sequences, pseudo random unique id

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От
Alvaro Herrera
Тема
Re: "ownership" of sequences, pseudo random unique id
Дата
Msg-id
20090820183102.GJ6261@alvh.no-ip.org
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"ownership" of sequences, pseudo random unique id Ivan Sergio Borgonovo <mail@webthatworks.it>
Re: "ownership" of sequences, pseudo random unique id Alvaro Herrera <alvherre@commandprompt.com>
Re: "ownership" of sequences, pseudo random unique id Ivan Sergio Borgonovo <mail@webthatworks.it>
Re: "ownership" of sequences, pseudo random unique id Tom Lane <tgl@sss.pgh.pa.us>
Ivan Sergio Borgonovo wrote:
> I've
> 
> create table pr(
>   code varchar(16) primary key,
>   ...
> );
> create sequence pr_code_seq owned by pr.code; -- uh!
> 
> pr.code will *mostly* be obtained as
> 
> to_hex(feistel_encrypt(nextval('pr_code')))
> and sometimes 'manually' inserting unique codes.
> 
> actually stuff like:
> alter table pr drop column code;
> or just
> drop table pr
> 
> seems to work as expected (they drop the sequence too).
> 
> Should I be concerned of anything since it looks like a hack?

You need to ensure you have a retry loop in your insertion code, because
if the generated code conflicts with a manually inserted code, it will
cause an error.  Other than that, seems like it should work ...

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.
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