Skip site navigation (1) Skip section navigation (2)

Re: [GENERAL] how to save a bytea value into a file?

From: Merlin Moncure <mmoncure(at)gmail(dot)com>
To: Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at>
Cc: "fanlijing *EXTERN*" <fanlijing(at)cn(dot)fujitsu(dot)com>, pgsql-admin(at)postgresql(dot)org, pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] how to save a bytea value into a file?
Date: 2011-10-10 15:51:14
Message-ID: CAHyXU0y06Q-ujZG+jcvbOuycdv1x9MgeDxfmnWSmqfYK0Bu0uw@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-adminpgsql-general
On Mon, Oct 10, 2011 at 9:26 AM, Albe Laurenz <laurenz(dot)albe(at)wien(dot)gv(dot)at> wrote:
> I wrote:
> [fanlijing wants to write bytea to file]
>> A simple
>>    COPY (SELECT byteacol WROM mytab WHERE ...) TO 'filename' (FORMAT
> binary)
>> should do the trick.
>
> Corrections:
> a) "binary" must be surrounded by single quotes.
> b) that won't dump just the binary data - you would have
>   to remove the first 25 bytes and the last 2 bytes...
>
> So maybe using the functions I mentioned would be the
> best way after all.
>
> You could also write your own user defined function in C.

A user defined function,  or a binary wire format speaking client side
extractor in C/libpq.  The basic rule of thumb for me regarding C
inside the server is 'only when no other reasonable solution exists'.

merlin

In response to

pgsql-admin by date

Next:From: Akash KodibailDate: 2011-10-10 15:54:57
Subject: Postgres Server crashed
Previous:From: Albe LaurenzDate: 2011-10-10 14:26:26
Subject: Re: [GENERAL] how to save a bytea value into a file?

pgsql-general by date

Next:From: Mark KeislerDate: 2011-10-10 16:05:17
Subject: streaming replication
Previous:From: John R PierceDate: 2011-10-10 15:29:49
Subject: Re: Postgres 9.01, Amazon EC2/EBS, XFS, JDBC and lost connections

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group