RE: Using BLOBs with PostgreSQL

From: Franck Martin <Franck(at)sopac(dot)org>
To: "'Martin A(dot) Marques '" <martin(at)math(dot)unl(dot)edu(dot)ar>, "'Tim Kientzle '" <kientzle(at)acm(dot)org>, "'PostgreSQL general mailing list '" <pgsql-general(at)postgresql(dot)org>
Subject: RE: Using BLOBs with PostgreSQL
Date: 2000-10-07 23:42:44
Message-ID: F12ECEA0435AD211B5280008C7ACBC857FEEA0@BIGIRON
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PG definitively lack BLOB support and it is a big drawback...

Even with PG7.1 with TOAST that will remove the 8kB limit on records, there
will be still no BLOB support.

As you have indicated it seems that PG chokes on null characters. What is
needed is a varbinary type, which stores binary data unformated, and spits
out the binary data inside a PQResult. Some additional funtions are needed
to read and write chunk of data inside that varbinary type.

Any volunteer amongst the hackers ?

I may try to do it as a used defined type inside a shared library, but I
think PG as is may not handle it correctly...

Cheers
Franck(at)sopac(dot)org

-----Original Message-----
From: Martin A. Marques
To: Tim Kientzle; PostgreSQL general mailing list
Sent: 8/10/00 11:11
Subject: Re: [GENERAL] Using BLOBs with PostgreSQL

On Sat, 07 Oct 2000, Tim Kientzle wrote:
>
> I've been using MySQL for initial development; it has pretty
> clean and easy-to-use BLOB support. You just declare a BLOB
> column type, then read and write arbitrarily large chunks of data.
> In Perl, BLOB columns work just like varchar columns; in JDBC,
> the getBinaryStream()/setBinaryStream() functions provide support
> for streaming large data objects.

If you're talking about BLOB texts, just declare the column as text and
thats
all. In the case of binary data, I don't have an idea. I only work we
text
data.

> How well-supported is this functionality in PostgreSQL?
> I did some early experimenting with PG, but couldn't
> find any column type that would accept binary data
> (apparently PG's parser chokes on null characters?).
>
> I've heard about TOAST, but have no idea what it really
> is, how to use it, or how well it performs. I'm leery
> of database-specific APIs.

As far as I have listen, it looks like a nice way to optimize searches
in
blobs. Don't know anything else.

Saludos... :-)

--
"And I'm happy, because you make me feel good, about me." - Melvin Udall
-----------------------------------------------------------------
Martín Marqués email: martin(at)math(dot)unl(dot)edu(dot)ar
Santa Fe - Argentina http://math.unl.edu.ar/~martin/
Administrador de sistemas en math.unl.edu.ar
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