Thread: efficiency question
03-30-11, 11:52 #1Registered User
- Join Date
- Mar 2011
Unanswered: efficiency question
i'm designing a database and i came to this question.
now i have a number of cars from different brands. all car brands have some
common properties (column) , but there are properties belong to specific
so which is better: to create a table for each brand having common
properties and special properties ;or to create a table for common properties
which will have differnt brands and a table for each brand having only its
special properties ?
i appreciate your help.
03-30-11, 17:48 #2Registered User
- Join Date
- Jan 2003
- Nottinghamshire, UK
Hi htb & Welcome
It's a bit of a Judgement call based on how many brands of Cars you expect & how specific the differences will be.
As a General Car Trader you may have 500 Brands in a year and not require specific details so much, As a Peugot Dealer you may have 20 Brands and want to record high amounts of detail.
Just ask yourself can you imagine creating a database with 500 tables to begin with ?
Something to look at would be using Supertypes and Subtypes Lesson 5: Supertypes and Subtypes be carefull though it does have disadvantages later on for beginners.
GW"Everything should be made as simple as possible, but not simpler." - Albert Einstein
"Everything should be made as complex as possible, so I look Cleverer." - Application Developer