psql ERROR : Character Types Tuple is too big: size xxxxx

Hi,

>From Bruce online book :
"There are synonyms for the terms table, row, and column. Table is more
formally referred to as a relation or class, row as record or tuple, and column
as field or attribute.
"
====
8Kb limit apply to :
'tuple' when insert ?
'tuple' in design stage (what's append with fixe types) ?
column (Case of fixe types) ???

What's wrong ?
- Design database
- Postgresql limit
Can't find informations on documentation and mail archive's obscure on 8Kb
limit.

Thanks fo help.
Emmanuel DISCORS
http://www.advl.org/kiwi/
===================
Error under psql interface :

A) The tuple in the 'insert' is < 8K but the tuple in table
description is > 8Kb

newkiwi=> insert into localisation values ('999', 'ee', 'ff', '999', 'gg',
'hh', 'ii', 'jj', '999'); ERROR: Tuple is too big: size 12356
newkiwi=> \d localisation
Table = localisation
+----------------------------------+----------------------------------+-------+
| Field | Type | Length|
+----------------------------------+----------------------------------+-------+
| id_loc | int4 not null | 4 |
| voie_loc | char() | 2048 |
| codebat_loc | char() | 2048 |
| idplan_loc | int4 | 4 |
| xplan_loc | char() | 2048 |
| yplan_loc | char() | 2048 |
| acces_loc | char() | 2048 |
| accesen_loc | char() | 2048 |
| id_ville_loc | int4 | 4 |
+----------------------------------+----------------------------------+-------+
Indices: localisation_pkey
localisationi1
localisationi2
localisationi3

B) The tuple in the 'insert' is < 8K and the tuple in table
description is < 8Kb

newkiwi=> insert into localisation values ('999', 'ee', 'ff', '999', 'gg', 'hh', 'ii', 'jj', '999');
INSERT 62016 1
newkiwi=> insert into localisation values ('999', 'ee', 'ff', '999', 'gg', 'hh', 'ii', 'jj', '999');
ERROR: Cannot insert a duplicate key into a unique index
newkiwi=> insert into localisation values ('9998', 'ee', 'ff', '999', 'gg', 'hh', 'ii', 'jj', '999');
INSERT 62018 1
newkiwi=> \d localisation
Table = localisation
+----------------------------------+----------------------------------+-------+
| Field | Type | Length|
+----------------------------------+----------------------------------+-------+
| id_loc | int4 not null | 4 |
| voie_loc | char() | 1024 |
| codebat_loc | char() | 1024 |
| idplan_loc | int4 | 4 |
| xplan_loc | char() | 1024 |
| yplan_loc | char() | 1024 |
| acces_loc | char() | 1024 |
| accesen_loc | char() | 1024 |
| id_ville_loc | int4 | 4 |
+----------------------------------+----------------------------------+-------+
Indices: localisation_pkey
localisationi1
localisationi2
localisationi3
===============================================