On 10/08/2014 10:22 AM, Emi Lu wrote:
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
Why do you need to ask if you already have the answer? Depesz is right.
cheers
andrew
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