Table Size - Normalization

[Charles Phillips]

Hello,
When designing a database, what is considered normal table size???
a.. How many fields should a table contain?
b.. I know trial & error is the best way to learn, but if you are reading
materials from authors of books, how do you determine what is best?????
c.. I read, making field combo boxes or list boxes reduces the execution
speed of your database, & should be avoided, is this true???
d.. Is it good or bad practice to make ALL your fields text??
e.. When should you let the database system determine the tables to be
made from 1 large table????

Thank you,

Charles L. Phillips

 

[Douglas J. Steele]

Answers in-line

--
Doug Steele, Microsoft Access MVP

(no private e-mails, please)

Hello,
When designing a database, what is considered normal table size???
a.. How many fields should a table contain?

A table should contain as many fields as are appropriate. There's no other
rule.

How you learn what's "appropriate" is where the skill enters into database
design <g>

Jeff Conrad has a number of references for database normalization at
http://home.bendbroadband.com/conradsystems/accessjunkie/resources.html#DatabaseDesign101

b.. I know trial & error is the best way to learn, but if you are reading
materials from authors of books, how do you determine what is best?????

Jeff points to a number of excellent lists of good resources at
http://home.bendbroadband.com/conradsystems/accessjunkie/resources.html#Books

c.. I read, making field combo boxes or list boxes reduces the execution
speed of your database, & should be avoided, is this true???

If you're putting too many records into a combo or list box, you may run
into issues, but then too many records is inappropriate anyhow, as your
users won't want to have to scroll through that many records.

d.. Is it good or bad practice to make ALL your fields text??

If your data is all text, there's nothing wrong with that. If your data is
all numbers, there's nothing wrong with that either. The fields should be
the most appropriate type to represent your data.

e.. When should you let the database system determine the tables to be
made from 1 large table????

I never rely on Access to determine stuff like that, but I suppose if you're
stuck as to how to normalize your data, it might be a good place to start.

 

[Designing-Systems.com]

hi,

The database is usually structured using the relational database design
theory. It uses the concept of "normalized" tables.

This dictates that information is linked through primary keys and foreign
keys and distributed across tables. The distribution is accomplished to
reduce redundancy and to allow relating linked data.

Using a single table it is hard to summarize and present linked data.

However if you are dealing with a single entity and you do not expect that
there would be redundant data in any column; you can create one large table.

Your database design will depend on the entities and the links among the
entities.

Regards,

 

[Charles Phillips]

Hello,
"Thank You", I'll keep reading...


Charles L. Phillips

 

[Charles Phillips]

"Thank You", this is good to know...


Charles L. Phillips