Some questions

Hello!

There is table of character types in manual, where the 'text' type suggested
as the best choice. 'text' is variable length type and I think, that
fixed length's types (such as char(n)) will be faster, than variable
length's ones? Am I wrong?

The second question is more complex :) It about CREATE TABLE statement. Is
there difference between following statements?

create table aaa (i int2 UNIQUE);
and
create table aaa (i int2, CONSTRAINT aaa_i_key UNIQUE(i));

First case uses 'column constraint' and second - 'table constraint'. Manual
says: "A column constraint is an integrity constraint defined as part of a
column definition, and logically becomes a table constraint as soon as it
is created". Am I understand correctly - it is never mind where to define
(any) constraints - all of them does the same?

And last: what does it mean the following statement in the CREATE TABLE?

...
len INTERVAL HOUR TO MINUTE
...

Thank you :)

---
Vladimir Litovka <doka(at)webest(dot)com>