Обсуждение: Character set conversion

Hi All,

I have a client application that uses an 8 bit character set that is not
supported by Postgresql. I'm using UTF-8 to store data within my
database and would like to create a character set conversion converting
between my native set and Postgresql. I have all the information I need
as far as which 8bit value should be mapped to what UTF-8 'character'.

I read in the documentation about the 'Create conversion' command
writing a function to do the conversion job. Is this the best way
forward or are there better ways to attempt this? Is there any sample
code available for implementing such a conversion? I don't want to
reinvent the wheel here...

--
Kindest Regards,

Bastiaan Olij
e-mail/MSN: bastiaan@basenlily.nl
web: http://www.basenlily.nl
Skype: Mux213
http://www.linkedin.com/in/bastiaanolij

Bastiaan Olij <lists@basenlily.nl> writes:
> I read in the documentation about the 'Create conversion' command
> writing a function to do the conversion job. Is this the best way
> forward or are there better ways to attempt this? Is there any sample
> code available for implementing such a conversion? I don't want to
> reinvent the wheel here...

Look into the PG source code under
src/backend/utils/mb/conversion_procs.

While an add-on conversion procedure isn't too hard, I don't think
there's any way to define a whole new encoding without modifying the
source code --- the encodings are listed in some hard-coded tables
in the C code rather than being defined by a system catalog.  It
wouldn't be too hard if you don't mind running a custom Postgres
build; but if you do, then the best answer might be to cannibalize
one of the existing encoding names and just replace its conversion
procedures.

            regards, tom lane

On Mon, July 21, 2008 10:16 am, Tom Lane wrote:

> It wouldn't be too hard if you don't mind running a custom Postgres
> build; but if you do, then the best answer might be to cannibalize one of
> the existing encoding names and just replace its conversion procedures.

Actually, I'd recommend not doing that.  Instead, put in your encoding as
a new encoding, and send a diff of your changes to the Postgres team.  I
bet next release it would be a supported encoding, and you would be able
to upgrade without any issues...

Daniel T. STaal

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