Inserting / selecting rows with TIMESTAMP

Hello All,

I am new to PostgreSQL. For testing purposes I am copying data from an
Oracle database to a PostgreSQL database via Access.
When I encountered an insert problem in Access, I tried it directly in
PostgreSQL and here is the result.

I am very confused. Can anyone give me a hint?

Thanks,
Claire

P.S. I have encountered the problem with the following dates:
1998-04-05 02:00:00, 2000-04-02 02:00:00 and 2002-04-07 02:00:00 (it's a
bit fishy, isn't it)
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Table "hre_gaz"
Column | Type | Modifiers
--------+--------------------------------+-----------
poste | smallint | not null
gaz | smallint | not null
temps | timestamp(0) without time zone | not null
valeur | integer |
qual | integer |
type | character(1) |
Primary key: hre_gaz_pkey
Triggers: RI_ConstraintTrigger_462203,
RI_ConstraintTrigger_462209

RsqaDb=# insert into hre_gaz (poste,gaz,temps,valeur,qual,type)
RsqaDb-# values (3,1,'1998-04-05 02:00:00'::timestamp,6,1,'S') ;
ERROR: Cannot insert a duplicate key into unique index hre_gaz_pkey

RsqaDb=# select * from hre_gaz
RsqaDb-# where temps between '1998-04-05 02:00:00' and '1998-04-05 02:59:59'
RsqaDb-# ;
poste | gaz | temps | valeur | qual | type
-------+-----+-------+--------+------+------
(0 rows)

RsqaDb=# select * from hre_gaz where temps
RsqaDb-# between '1998-04-05 02:00:00'::timestamp
and '1998-04-05 02:59:59'::timestamp ;
poste | gaz | temps | valeur | qual | type
-------+-----+---------------------+--------+------+------
3 | 1 | 1998-04-05 01:00:00 | 54 | 1 | S
3 | 3 | 1998-04-05 01:00:00 | 10 | 4 | S
3 | 4 | 1998-04-05 01:00:00 | 4 | 1 | S
3 | 8 | 1998-04-05 01:00:00 | 39 | 12 | S
3 | 9 | 1998-04-05 01:00:00 | 35 | 4 | S
3 | 10 | 1998-04-05 01:00:00 | 6 | | S
28 | 1 | 1998-04-05 01:00:00 | 8 | 1 | S
28 | 4 | 1998-04-05 01:00:00 | 5 | 2 | S
28 | 5 | 1998-04-05 01:00:00 | 13 | 18 | S
28 | 8 | 1998-04-05 01:00:00 | 6 | 2 | S
28 | 9 | 1998-04-05 01:00:00 | 62 | 7 | S
28 | 10 | 1998-04-05 01:00:00 | 47 | | S
61 | 1 | 1998-04-05 01:00:00 | 5 | 2 | S
61 | 4 | 1998-04-05 01:00:00 | 12 | 4 | S
61 | 8 | 1998-04-05 01:00:00 | 15 | 4 | S
61 | 9 | 1998-04-05 01:00:00 | 47 | 5 | S
61 | 10 | 1998-04-05 01:00:00 | 47 | | S
99 | 6 | 1998-04-05 01:00:00 | 2 | 8 | S
99 | 8 | 1998-04-05 01:00:00 | 29 | 9 | S
99 | 9 | 1998-04-05 01:00:00 | 18 | 2 | S
99 | 10 | 1998-04-05 01:00:00 | 1 | | S
(21 rows)

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