Fact vs Dimension
Moderators: chulett, rschirm, roy
-
- Premium Member
- Posts: 729
- Joined: Tue Apr 28, 2009 10:49 pm
Fact vs Dimension
All,
Which table data will be loaded first?
how many keys can be created for Fact table?
how many keys can be created for Dimension table?
Yes...This is the interview questions...one of my friend recently faced the above questions.
Which table data will be loaded first?
how many keys can be created for Fact table?
how many keys can be created for Dimension table?
Yes...This is the interview questions...one of my friend recently faced the above questions.
Karthik
Re: Fact vs Dimension
So what do you think?
FACT / DIM ?
DS User
FACT / DIM ?
DS User
Fact table:It consists of foreign Keys and Measures(mostly Numeric values)
Dimension:It provides descriptive information relating to the foreign key in a fact.
there are 2 types schema in loading them:
1. Star
2. Snow flake( dimensions r broken into sub dimensions)
PLease correct me if i'm wrong..!!
Dimension:It provides descriptive information relating to the foreign key in a fact.
usually dimension tables are loaded first then fact tables followed by aggregrator tables...Eg:- in employee table i have ename empid sal
in manager table i have mname mid and sal
so there are two dimension table
1--> emp table contains enmae eid(PK) sal
2--> Mgr table contains mname mid(PK) sal
Fact table contains
eid(FK) mid(FK) esal and msal
there are 2 types schema in loading them:
1. Star
2. Snow flake( dimensions r broken into sub dimensions)
PLease correct me if i'm wrong..!!
....................Shanthi
-
- Premium Member
- Posts: 729
- Joined: Tue Apr 28, 2009 10:49 pm
Re: Fact vs Dimension
Fact table ? I'm sorry..i am unable to fit this concepts in my projects. i have created lot of jobs..thoughSURA wrote:So what do you think?
FACT / DIM ?
DS User
![Sad :(](./images/smilies/icon_sad.gif)
Karthik
-
- Participant
- Posts: 54607
- Joined: Wed Oct 23, 2002 10:52 pm
- Location: Sydney, Australia
- Contact:
Which will be loaded first? Whichever one you choose to load first.
However, there is a right way and a wrong way. And the wrong way is highly likely to throw errors, for example if referential integrity is enforced in the database (which it should be).
However, there is a right way and a wrong way. And the wrong way is highly likely to throw errors, for example if referential integrity is enforced in the database (which it should be).
IBM Software Services Group
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
-
- Premium Member
- Posts: 729
- Joined: Tue Apr 28, 2009 10:49 pm
Dimension table must be loaded first and then the fact table should be loaded.
Ref:
http://www.information-management.com/i ... gination=1
Am I correct?
Ref:
http://www.information-management.com/i ... gination=1
Am I correct?
Karthik
-
- Premium Member
- Posts: 1735
- Joined: Thu Mar 01, 2007 5:44 am
- Location: Troy, MI
-
- Participant
- Posts: 54607
- Joined: Wed Oct 23, 2002 10:52 pm
- Location: Sydney, Australia
- Contact: