Re: Toast and slice of toast - Mailing list pgsql-general

From Andres Freund
Subject Re: Toast and slice of toast
Date
Msg-id 20140217093738.GQ19470@alap3.anarazel.de
Whole thread Raw
In response to Re: Toast and slice of toast  (Haribabu Kommi <kommi.haribabu@gmail.com>)
Responses Re: Toast and slice of toast
List pgsql-general
On 2014-02-17 14:16:33 +1100, Haribabu Kommi wrote:
> On Sun, Feb 16, 2014 at 9:38 PM, Rémi Cura <remi.cura@gmail.com> wrote:
>
> > Hey Dear List,
> > could somebody point me to some ressources about getting only parts of
> > toasted data?
> >
> > I have a very big custom type and I would like to take blocks of it (like
> > byte A to B then byte C to D  then... ).
> >
> > I found a function in http://doxygen.postgresql.org/tuptoaster_8c.html#called toast_fetch_datum_slice, is it the
rightway to use it 
> > (a for loop and calling it several time?).
> >
>
> "pg_detoast_datum_slice" is the function which will solve your problem.

Note that you need to prevent your type/column from being compressed for
that being effective. Check the storage options for CREATE TABLE et al.

Greetings,

Andres Freund

--
 Andres Freund                       http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services


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