I would say that "it depends". You've got the field defined as a char(n) [which
I really wish you had specified what 'n' was]. Now is this field initially left
null and then later updated? Or will it be initially filled with a very small
value like '01' and then later updated to a larger (I guarantee) value? If so
then specifying it as a char will pre-allocate the entire field size at the
start thereby reducing the need to expand the filed at a later date. This can
help with fragmentation.
Now on the other hand, if this field is rarely if ever updated after it's
initial creation, a varchar2 is the better choice.
Dick Goulet
____________________Reply Separator____________________
Author: [EMAIL PROTECTED]
Date: 7/11/2001 1:25 AM
The definition of char and varchar2 is clear from docu that one is used for
fixed length and the other for variable.
We are reviewing one database desgin given to use from our developers in
that they have chosen to use CHAR(n)
data types at many places, even though the field can have variable lenght
data.
For example for a column as region_code it is set as char(5) not this value
can be '01' , 'CEN','WEST' etc
would it be wise to make it varhar2(5).
The reason is that if you want to query the colum in a where clause (if you
have chosen char(5)) then I think
you have post fix spaces unnecessarily right? (where region_code = '01
'
becuase region_code = '01' would return no rows.
1)
Any ones has any suggestions on how to choose char and varchar2 for columsn
that are small in lenght like < 30 characters and unsire of its fixed or
variable?
2)
Is there any implication if we convert all those small lenght columsn for
which we are not sure of data-lenght from char to varchar2???any side
affects in making varch2?
Regards
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