Re: R: feature proposal ... - Mailing list pgsql-hackers

So, that means copy doesn't support views? If it is like that, then why not
work in the View support for the Copy statement?

-----Original Message-----
From: pgsql-hackers-owner@postgresql.org
[mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Hans-Jürgen Schönig
Sent: Miércoles, 21 de Septiembre de 2005 08:04 a.m.
To: Paolo Magnoli
Cc: pgsql-hackers@postgresql.org; eg@cybertec.at
Subject: Re: R: [HACKERS] feature proposal ...

no because a new is not a heap ...

em=# create view x as select * from pg_class;
CREATE VIEW

em=# copy x to '/tmp/x';
ERROR:  cannot copy from view "x"
best regards,
    hans



Paolo Magnoli wrote:
> Can't you just use a view?
>
> -----Messaggio originale-----
> Da: pgsql-hackers-owner@postgresql.org
> [mailto:pgsql-hackers-owner@postgresql.org]Per conto di Hans-Jürgen
> Schönig
> Inviato: mercoledì 21 settembre 2005 15.30
> A: pgsql-hackers@postgresql.org; eg@cybertec.at
> Oggetto: [HACKERS] feature proposal ...
>
>
> hackers,
>
> currently we have to hack tons of export scripts for various customers.
> the problem is: if tables can be exported straight forward COPY will
> give you all you need but when data has to be transformed while
> exporting things start becoming a bit more complex. usually people want
> to have CSV file (excel-ify data) which is supported by COPY.
>
> the problem is: COPY can write data returned by a SELECT statement to a
> file. our idea is to implement precisely that.
>
> example:
>
> COPY TO file_name USING some_select_statement;
>
> the advantage would be that COPY would then be able to export data and
> transform it on the fly. this would save many people a lot of work
> because complex data extractors could in many cases be replaced by
> simple SQL scripts.
>
> how we plan to implement that:
> currently copy simply opens a table and loops through the tuples (see
> command/copy.c starting at line 1115).
> to implement the desired feature we just had to add some SPI code to the
> scenery (SPI will also return HeapTuples so it should fit in there).
>
> Any comments?
>
>     Best regards,
>
>         Hans
>
>
> --
> Cybertec Geschwinde & Schönig GmbH
> Schöngrabern 134; A-2020 Hollabrunn
> Tel: +43/1/205 10 35 / 340
> www.postgresql.at, www.cybertec.at
>
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--
Cybertec Geschwinde & Schönig GmbH
Schöngrabern 134; A-2020 Hollabrunn
Tel: +43/1/205 10 35 / 340
www.postgresql.at, www.cybertec.at

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