Seperating tables for performance?

[bilbo66]

Hi,

I am working on a small db for a non-profit.
It is an Organisation db, one field in the main table is a description field, type memo.
Now we will be filling this field slowly overtime,
so shall have plenty of nulls.
Should I have a seperate table and link it with a foreign key?
Would this speed up the performance of the db, or not?
This field will be searched.

Also,
My co-worker thinks if we haven't filled in a field we should set a default value of "Unknown".
Would this be better unfilled for db performance?

Any comments welcome,
thanks in advance.
Bill.

 

[JoeMiller]

IMHO you should not put in "Unknown" as a value not because of performance reasons (though it would help space) but because it's simply bad design. Databases should really only store as little information as they need to and since you can look at the value of a field and display "Unknown" if it's null, literally typing in "Unknown" is a waste of the user's time. Another issue that this presents is having to use text fields everywhere so you can store "Unknown" and not taking advantage of Access' different data types is a bad idea!

Here's a sample of the type of code you can use on reports to display "Unknown" for presentation purposes when the data is displayed to the user:

[tt]
=IIf(IsNull([MyFieldName]),"Unknown",[MyFieldName])
[/tt]

My two cents, hope that helps.

Joe Miller
joe.miller@flotech.net

 

[bilbo66]

Thanks for the input.
I didn't like the idea of the many "unknowns".
Our db users won't be typing in this each go, as it can be set as a default value.
I like your idea, but if the text field is bound, won't it end up with "unknown" anyway?

Plus have you any ideas about splitting the table:

tblOrgs

Fields:

OrgID
Address and detail fields....
Comment as memo
Description as memo
or

tblOrgs
OrgID
Address and detail fields....

and

tblDescription
OrgID
Comment as memo
Description as memo

Is there any advantage to splitting the tables?

Any thoughts?
Bill.

 

[LarryDeLaruelle]

Bill:

Unless there will be a one to many relationship between the two tables (that is, one Organizations could have many Descriptions) then no, don't split.

Will the descriptions be so long as to require a memo field? A regular text field will give you up to 255 characters to use.
Larry De Laruelle
larry1de@yahoo.com