The speed problem of Varchar vs. Char

[Crystal <support@xxxxxxxxxxxxxxxxxxx>]

Hi All,

Our company need to save contact details into the PostgreSQL database. I 
just begin to learn it, so I got many questions. I am not sure which 
data type I should choose for website address, varchar or char. The 
website address may be very long, and we also don't want to lose the 
speed. Thus, the question is: if we have a large contact database, how 
much slowdown or speed up will be expected if we choose variable length 
rather than fixed length? Thanks forward.

Best Wishes,
Crystal