Blobs in PostgreSQL

There are many things one may mean by blob.
a) there's old 'large object' interface,
http://www.postgresql.org/idocs/index.php?largeobjects.html

b) the above is rarely necessary now, that there is no limit on amount of
data you can put into one tuple (due to TOASTing of tuples). To store
binary data, you should use bytea type and it has infinite (well, 4G)
limit of data.

On Wed, 27 Jun 2001, Richard Church wrote:

* Alex Pilosov <alex@pilosoft.com> wrote:
|
|
| b) the above is rarely necessary now, that there is no limit on amount of
| data you can put into one tuple (due to TOASTing of tuples). To store
| binary data, you should use bytea type and it has infinite (well, 4G)
| limit of data.

Well, the bytea datatype is not supported by the JDBC driver.
Also it is not documented in the datatype section of the manual.

--
Gunnar R�nning - gunnar@polygnosis.com
Senior Consultant, Polygnosis AS, http://www.polygnosis.com/

On 27 Jun 2001, Gunnar [iso-8859-1] R���nning wrote:

Well, the bytea datatype is not supported by the JDBC driver.

Can't do much about that...

Also it is not documented in the datatype section of the manual.

It [will be] in 7.2 and its documented in CVS now :)

Can it be created and manipulated using the SQL syntax, or does it require
using the C language interface?

From: Alex Pilosov <alex@pilosoft.com>
To: Richard Church <rfchurch@hotmail.com>
CC: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Blobs in PostgreSQL
Date: Tue, 26 Jun 2001 22:22:29 -0400 (EDT)

There are many things one may mean by blob.
a) there's old 'large object' interface,
http://www.postgresql.org/idocs/index.php?largeobjects.html

b) the above is rarely necessary now, that there is no limit on amount of
data you can put into one tuple (due to TOASTing of tuples). To store
binary data, you should use bytea type and it has infinite (well, 4G)
limit of data.

On Wed, 27 Jun 2001, Richard Church wrote:

It seems that PostgreSQL supports Blobs but I couldn't find any mention

of

it in the data types section of the manual.

Is it a variant on the Text type, or is it entirely different?

Where in the manual is it described?

Richard

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SQL syntax is fine.

On Wed, 27 Jun 2001, Richard Church wrote:

Any examples available, please?
On all of creating, insertion, updateing, setting it to null?

From: Alex Pilosov <alex@pilosoft.com>
To: Richard Church <rfchurch@hotmail.com>
CC: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Blobs in PostgreSQL
Date: Wed, 27 Jun 2001 08:43:33 -0400 (EDT)

SQL syntax is fine.

On Wed, 27 Jun 2001, Richard Church wrote:

Can it be created and manipulated using the SQL syntax, or does it

require

using the C language interface?

From: Alex Pilosov <alex@pilosoft.com>
To: Richard Church <rfchurch@hotmail.com>
CC: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Blobs in PostgreSQL
Date: Tue, 26 Jun 2001 22:22:29 -0400 (EDT)

There are many things one may mean by blob.
a) there's old 'large object' interface,
http://www.postgresql.org/idocs/index.php?largeobjects.html

b) the above is rarely necessary now, that there is no limit on amount

of

data you can put into one tuple (due to TOASTing of tuples). To store
binary data, you should use bytea type and it has infinite (well, 4G)
limit of data.

On Wed, 27 Jun 2001, Richard Church wrote:

It seems that PostgreSQL supports Blobs but I couldn't find any

mention

of

it in the data types section of the manual.

Is it a variant on the Text type, or is it entirely different?

Where in the manual is it described?

Richard

_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

For which ones?

For bytea fields, you can just use regular functions (substring, etc), and
there's no (well, 2G) limit on size of the field.

For real blobs, its more involved. You are _very strongly suggested_ to
use client-side interfaces, and not SQL interface. (What's the point of
using SQL to fetch a piece of blob on server? What are you going to do
with it? )

On Thu, 28 Jun 2001, Richard Church wrote: