Good morning,

For performance point of view, are there big differences between: char(N), varchar(N), varchar, text?

Some comments from google shows:
No difference, under the hood it's all varlena. Check this article from Depesz: http://www.depesz.com/index.php/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/
A couple of highlights:

To sum it all up:

char(n) – takes too much space when dealing with values shorter than n, and can lead to subtle errors because of adding trailing spaces, plus it is problematic to change the limit

varchar(n) – it's problematic to change the limit in live environment

varchar – just like text

text – for me a winner – over (n) data types because it lacks their problems, and over varchar – because it has distinct name

So, can I assume no big performance differences?
Thanks alot!
Emi