Daniel Morgan wrote:
> Comments in-line.
>
> xtanto wrote:
>
>> Hi gurus,
>>
>> I have two design question, could you please give some reccomendation
>> :
>>
>> (1) Instead of CHAR, I plan to use VARCHAR2 for all character type
>> column. This is to avoid having to use RTRIM for char comparison from
>> within Forms application. Is there any bad impacts of this design
>> decision ?
>
> No.
You mean, apart from the fact that having variable data in the row instead
of fixed means you have to allow greater PCTFREE to accommodate potential
row growth? And a higher PCTFREE means more wasted space... and more wasted
space means longer full table scans... and longer full table scans equates
to poorer performance...
I'd go varchar2, too, but to say there are no costs in doing so is
stretching it a bit...
Regards
HJR
>
>> (2) We have two tables of organization membership, one for 'permanent'
>> member , the other for 'non-permanent' member. After two years,
>> non-permanent member will become permanent member. The permanent
>> member is 4.000.000 rows and the non permanent member is about 200.000
>> rows.
>> These two tables are separated because there are reports that are only
>> dedicated to Non-permanent member, so that the query will be faster.
>> BUT there are also reports that combine the two tables using UNION.
>> Is using UNION with this amount of rows will cause any bad performance
>> ?
>> Or these two table should be only one tables using member-type column
>> ?
>>
>> Thank you for any comments,
>> xtanto
>
> Combine the tables. Your design is non-relational and guaranteed to
> create problems.
Received on Sun Oct 03 2004 - 01:47:59 CDT
