Re: char vs varchar ?

In article <3nr1c3$5so_at_maverick.tad.eds.com>, rew_at_sfsv.opr.eds.com wrote:

>In article <3n5vrf$bqo_at_cardinal.fs.com>,
 skannan_at_PROBLEM_WITH_INEWS_GATEWAY_FILE ( S. Kannan) says:
>>
>> Varchar and Varchar2 are currently synonymous. However Oracle Corporation
>> may change the way Varchar works, in a future version.
>>
>> The difference between char and varchar in Oracle 7 and above is that
>> char is fixed length and can store upto 255 characters. Varchar (or
>> Varchar2 currently) is variable length and can store upto 2000 bytes
>
>With Oracle 7, is their a performance decrease when using both fixed and
 varchar fields?
>
>We are designing a database using a CASE tool. We want to use both fixed
 and varchar fields
>because the database will be generated for both Oracle (on the
 workstation) and DB2
>(on the mainframe). DB2 runs faster with fixed fields than varchar fields.
>
>Now another group will access our database with other tools, including
 Oracle Forms.
>They want us to define all fields as varchar instead of our current
 design, which mixes
>fixed and varchar fields.

i tested this a while back and could find no performance difference between char and varchar2, aside from the fact it sometimes needs to add a bunch of spaces to the former. i *expected* char's to be faster for short fixed-length string, but they were not. who knows what might happen in the future, though. i still think CHAR makes sense for some applications - if you are careful - for the same reason that it made sense to use integrity constraints in oracle 6, even tho they weren't enforced. Received on Wed May 03 1995 - 00:00:00 CEST