String comparison problem.

Dear All,

I have some problem with string comparison. I use
postgresql 8.3.1,UTF8 encoding, on CentOS 5.5. Why dose the result of
SQL statement : "select '1.1' < '101';" is false but "select
'1.1'::bytea < '101'::bytea;" is ture?

mis=# select '.' < '0';
?column?
----------
t
(1 row)

mis=# select '1.' < '10';
?column?
----------
t
(1 row)

mis=# select '1.1' < '101';
?column?
----------
f
(1 row)

mis=# select '1.1'::text < '101'::text;
?column?
----------
f
(1 row)

mis=# select '1.1'::bytea < '101'::bytea;
?column?
----------
t
(1 row)

Thank you very much.