Date: Sun, 3 Nov 2002 16:38:45 -0800 (PST)
From: Stephan Szabo <sszabo@megazone23.bigpanda.com>
To: <pilsl@goldfisch.at>
Cc: Doug McNaught <doug@mcnaught.org>, <pgsql-general@postgresql.org>
Subject: Re: 7.2.3: tuple is too big (max 8136)
In-Reply-To: <20021104011105.A11131@goldfisch.at>
Message-ID: <20021103162643.V91168-100000@megazone23.bigpanda.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Mon, 4 Nov 2002 pilsl@goldfisch.at wrote:

> On Fri, Nov 01, 2002 at 08:50:54AM -0500, Doug McNaught wrote:
> >
> > It's possible you are hitting the maximum column limit rather than the
> > tuple size limit.  The FAQ list the max columns in a table as:
> >
> > "250-1600 depending on column types"
> >
>
> I already created the table with 1600 cols of varchar(30) so this
> should not be the limit. And the errormessage is clearly talking about
> the tuples size. (which should not have such a limit in 7.2.3).

Technically there is still a tuple size limit.  It's just that many types
can be pulled out of the main storage of the table and you get a reference
to its value in the main storage rather than the value itself.  That's how
the 8k limit was circumvented.  The tuple size limit is part of why
there's a maximum column count, AFAIK the main tuple still needs to fit in
one page. The create table may succeed even if it's not possible to
actually insert non-null values in every column (for example, make a table
with 1400 int8 columns, if you try to insert values into each column,
it will fail.  If you try to insert say only a few values and alot of
nulls, it works).