On Jan 18, 2007, at 15:15 , Gene wrote:
My calculations for disk space based off some information i found
online are ( 8 + ( 2 bytes for every four digits) ) for numeric and (
4 + number of chars ) for a utf8 varchar datatype. Are these
calculations still valid and has anyone tried using numeric for this
purpose or is this really stupid?
While telephone numbers typically consist of digits, they're not
numbers: they're strings of digits. For example, a telephone number
in Tokyo is (typically) a string of 10 digits, beginning with "03".
0311111111 as numeric would have unexpected results when retrieved.
While you may not be concerned with Japanese phone numbers, I use it
as an example to show that telephone "numbers" are actually strings.
In short, use strings (text/varchar).
Michael Glaesemann
grzm seespotcode net
PS. The number of bytes used to represent characters in UTF-8 varies.
I believe digits (0-9) are all 1 byte/char.
