All Questions
162
questions
-1
votes
2
answers
87
views
Can I use the same field to reference two tables, which both ultimately reference the same table?
I have designed this database to add trees to a forest, each forest is only allowed one type of tree. I want to make sure all trees added to the forest via the "forest_has_tree" table are of ...
0
votes
1
answer
148
views
Fitting a warehouse pricing tariff into MySQL tables
Creating the right database structure from a manual tariff
I have been assigned a rather challenging database design and thought someone may be able to give me a few pointers to help get going. We ...
- 85
-1
votes
1
answer
2k
views
Partial dependency
Suppose we have a relation R(A,B,C,D,E) with candidate keys {A,B} , {C,D} and let E be a non prime attribute.
If there is a dependency C->E then it is partial dependency as E depends on a part of ...
- 1,581
-2
votes
2
answers
460
views
Why is this table in 3NF?
Consider the following table:
The primary key is a composite key consisting of PatID and PhysName. My professor says this table is in 3rd normal form. I thought it's not even in second normal form ...
- 2,480
0
votes
1
answer
1k
views
Database Design review
I have an old database design that I think I can streamline and make more normalized. I was hoping to get some thoughts on this. Here are the “rules” for the database:
The organization is made up ...
- 3,555
0
votes
1
answer
231
views
if relation R(A,B,C,D,E) with FDs {AC->B, AC->E, B->C}. What is highest normal form satisfied
Here in FDs Attribute D is not included in any of FD so should we ignore it ? is there any rule which specifies that all attribute should be part of atleast on FDs?
As per my understanding this is ...
-1
votes
1
answer
61
views
Should i normalize or denormalize my database for reservation system?
I'm trying to design my database for our Reservation System, but the thing is i got confused whether should i still Normalized my Database or not .
My question is that whether is it really ...
0
votes
2
answers
63
views
How to represent "to be approved" elements in database
I have a model where it has an attribute called type that is a type of a user's bag (substitute entities for confidentiality).
Users can have multiple Bags (one to many)
Bags have only one Type
Type ...
user3717115
1
vote
1
answer
1k
views
Why is given example not in 3NF?
I have following example which I am trying to understand, where:
R = {A, B, C}
FD = {A->B, B->C, AB->C}
Prime key is A.
I know that this example is in 2NF, because prime key has only one ...
- 936
0
votes
1
answer
51
views
Rendering DB values using Javascript
Till date in a project of mine there has been straight forward implementation of DB normalization and the way "status codes" are stored , for example
Patient_table
patientId | referralStatus
...
- 142
0
votes
0
answers
54
views
Is this database normalized enough?
I was wondering if you guys could look at this database design and tell me if it normalized to the best it can be. Likewise, if you see any problems or improvements.
The database is essentially has ...
- 13
1
vote
1
answer
574
views
Minimum no of tables that exists after decomposing relation R into 1NF?
Consider the relation R(A, B, C, D, E, F, G) with the following types of attributes:-
Total No of Keys = 1 = {A}
Set of Simple (or) Atomic (or) Single Valued Attributes = {B, C}
Set of Multivalued ...
1
vote
2
answers
87
views
Normalised vs. denormalised database for similar data
I am planning to build a database where I store a large amount of data about music.
I am storing song-specific information in the db_song table.
I'd also like to store genres, instruments, samples and ...
- 13
0
votes
1
answer
67
views
Normalize or not - one to many or lots of columns
I cannot decide whether to normalize or denormalize this part of my database:
I have a list of ~50 species that are either present or absent at a given sample point. These 50 will maybe expand to 75 ...
- 109
0
votes
1
answer
204
views
MySQL - Storing Default Values for System
I have a few tables storing their corresponding records for my system. For example, there could be a table called templates and logos. But for each table, one of the rows will be a default in the ...
- 2,335