On Tuesday 22 June 2004 11:26 pm, Madison Kelly wrote:
> Something I have been wondering about and haven't found an answer to
> yet is how the size of a datatype (I hope that is the right term)
> effects performance. What effect is there if I specify "TEXT" instead of
> say "VARCHAR(255)"? How much benefit is there do being more aggresive
> and say cutting it in half again by using "VARCHAR(128)"?
There is no performance difference between varchar, char and text. Infact,
text is equal to varchar with no length specified (a Postgresql extension).
I use varchar when I want a max limit on the number of characters. Char when
I want a set number of characters (auto space padded). And use text all
other times, because it is more readable than varchar.
All this and more can be found in the Docs - 7.4.2: Ch 8: Data Types, Sec 8.3:
Character Types.
good luck,
Vams