Yumiko Izumi <izumi-yumiko(at)scnet(dot)co(dot)jp> writes:
> When I carried out SQL sentence in PostgreSQL7.3.8 environment,
> PostgreSQL outputs the following error messages.
You haven't shown us the failing SQL command, nor indeed anything else
that would let someone else reproduce the problem. However, 7.3.8
is more than two years old, so your first step ought to be to update
to a more recent release to see if the problem is already fixed.
regards, tom lane