Normalization is the process of organizing columns into tables within a relational database in such a way as to minimize redundancy and avoid insertion, update and deletion anomalies.

learn more… | top users | synonyms

0
votes
0answers
11 views

Normalization questions with non-real world examples

I have a few questions regarding normalization. I'm aware these may be terrible examples from a practical point of view, but I need to understand how normalization theory applies to them. 1) Table: ...
0
votes
0answers
12 views

Two id columns in one detail table

Let's I have two tables(I have removed some columns for brevity): ADULTS -> ID CHILDS -> ID And I have one table which includes detials about these persons like that: USERS-> ADULT_ID, ...
0
votes
1answer
50 views

Normalization for three somehow identical tables

These three tables are nearly identical. But, there are some exceptions. But, I can't find best normalized structure. Could you please help me? Here is the informations must be hold in database: ...
2
votes
1answer
36 views

Why wouldn't I put the single preferred option into its own table, instead of having a 'Preferred' column?

In similar spirit to How to implement a 'default' flag that can only be set on a single row I would like to specify that, for any given list of possible names for a business, only one of the ...
2
votes
1answer
93 views

Should database be denormalized if I need an index across multiple tables

I have a catalog of album and song names. The song has a foreign key to the album table. I expect queries like: SELECT * FROM song s JOIN album a ON a.id = s.album_id WHERE LOWER(CONCAT_WS(' ', ...
2
votes
1answer
79 views

Reporting on a normalized Key-Value pivot

ERD & SQL Fiddle provided. We're trying to design a reporting tool for our stakeholders around a normalized Key-Value Pair model. We've tried to find a solution using Pivot Tables but can't seem ...
0
votes
2answers
729 views

Question regarding 2NF partial key dependency

If the functional depencies are AB-->CD BC-->D IS the relation still in 2NF?,I mean since AB is the key and the 2nd BC,out of which B is part of the key,is the relation still in 2NF??
1
vote
2answers
49 views

Should I normalize my string arrays, or just keep it a simple string?

I am working on a project involving cards from the Magic: The Gathering game. To be of any use, I must load the basic information about each card into my database, but some of the fields may contain ...
-4
votes
1answer
47 views

Create database unique Surrogate Keys without using GUID’s

What is the best way to get database unique surrogate keys in Microsoft SQL Server when using something like “auto increment” as opposed to GUID's. The purpose is to increase performance over using ...
0
votes
1answer
51 views

Normalising Customers and Employers with a people table

At what normalisation stage is it recommend to split say Customers and Employees into a people table and then link to the unique attributes of Customers and Employees. I cant seem to find the ...
2
votes
1answer
53 views

On modeling pairs with a possibly empty second element

EDIT: I've made the post significantly shorter. I hope it's more digestible now. Consider the following schema: CREATE TABLE X ( x TEXT PRIMARY KEY ); CREATE TABLE Y ( y TEXT PRIMARY ...
4
votes
0answers
85 views

Transforming table to third normal form

I have a table like this: L(A, B, C, D, E) and functional dependencies are: AB -> CDE C -> D D -> B D -> E I need to transform this table into 3NF. I think it's not even in 2NF. I ...
1
vote
1answer
27 views

Trying to get BCNF out of this relation

The table is: Employee ( EID, Ename, PID, ProjectName, MID, ManagerName ) For the functional dependencies I got: EID==>(Ename) PID==>(ProjectName) ...
3
votes
1answer
79 views

Database Normalization

If someone could guide me on helping me understand if my results are correct I would appreciate that. Let's say I have the following table: BOOK(BookTitle, AuthorName, BookType, ListPrice, ...
1
vote
1answer
51 views

Normal Form question

Hey guys I am trying to study for an exam and I cant seem to get my head around normal forms. here is one question: R1 [a b c] fd1: {a,b} -> {c} fd2: c -> b I know the candidate keys are {a,b} {a,c} ...
1
vote
1answer
65 views

Normalization to 2NF and 3NF

I solved this example to determine 2NF and 3NF. I would like to check if my answer is correct. Can somebody check the 2NF and 3NF of this example, please? R( A B C D E F G H I J) with functional ...
1
vote
2answers
35 views

How to normalize a table that contains a CK not included in the PK?

I have the following table. The PK is model_ID. Assuming that the modelName field is unique(that is, no two brands can have an identical modelName), there is a transitive dependency between modelName ...
0
votes
2answers
54 views

Normalising shared entities and applying constraints

I'm looking for a specific "best practice" or "pattern" concerning entities that are shared between different entities, having a relation to one of many. For example, one may have the generic entity ...
1
vote
1answer
83 views

Normalizing: when to apply 2NF and 3NF [closed]

I am taking college classes in relational databases for half a year now. As an assignment get to normalize data with 1NF, 2NF and 3NF. I do not find any difficulties making my schema compatible with ...
0
votes
1answer
27 views

Using part of a compound key as foreign key

We have the following situation, in which we have three tables: Article ------- - Id (PK) - Supplier_Id - Supplier_Contactperson_Id - Name Supplier --------- - Id (PK) - Name SupplierContactperson ...
1
vote
3answers
1k views

how to convert a table into second normal form

I am really struggling to convert the table into second normal form ive tryed examples which are much easier however i can't seem to be able to identify the keys for this one and work my way forward. ...
2
votes
1answer
158 views

Dependency preserving and lossless join decompositions

I have a relation: R = {A, B, C, D, E, F, G, H, I, J} And a set of functional dependencies: G = {AB -> C, A -> DE, B -> F, F -> GH, and D -> IJ} I ended up decomposing into two ...
1
vote
1answer
53 views

Clarification for database creation and relations

I've trying to make database with few tables and relations between them. As I'm not very good in databases at all I need some clarifications. The idea is to connect table with table_1, table_2 and ...
-5
votes
1answer
112 views

normalization NF1, NF2, NF3 [closed]

Pls I need an urgent help ,Can you create a Student school Transcript normalization NF1, NF2, NF3 in excel..... I actually need for someone to help me create a database of " Student School ...
1
vote
2answers
109 views

Train Fare Database Normalisation

I have a database to normalize. The database has details of train ticket fares. The trains have different fares depending on the distance and I have to store these fares in the database It is not an ...
0
votes
1answer
42 views

what should be the good normalization for the following scenario?

ITS JUST FAKE TABLE DATA TO SIMPLIFY MY PROBLEM I have tables ,, Users , shirts, pants, belts .... each will have some data... so by some research i have made some scenarios of links between the ...
1
vote
1answer
73 views

Normalized database table with non-atomic values

I'm creating a normalized table for a questionnaire that the customers fill in and in one of the columns is a field called "extra comments". I realize that with the "extra comments" field, the data ...
1
vote
1answer
89 views

Index optimization on a view using a full outer join

Table structure: Foo FooChild Bar --- -------- --- ID ID ID Date FooID Date ...
2
votes
1answer
133 views

How to model schedule and keep good constraints?

I have some data that I am having a hard time modeling. Particularly, I am unsure of how I can ensure that I have unique data. This is for a schedule where I am assigning teams to stores. A team will ...
0
votes
0answers
42 views

Best way to store a function map

I am building a site where data gets filtered through user defined functions to create an output. It is a requirement that the functions are represented in the database as formulas. For example a ...
0
votes
1answer
77 views

Database Normal Form (financial statement)

I would like some advice on how to design the database for financial statement data which objectively addresses the tradeoffs between usability, performance, maintenance and adherence to normal form. ...
0
votes
1answer
72 views

Decompose Relation R(ABCDE) in 2nf and 3nf

Given relation R(ABCDE) with functional dependencies A->C B->D AB->E Given: AB is the primary key. I know that this relation is in 1NF because of partial dependencies A->C and B->D Now how I ...
4
votes
5answers
902 views

What normal form does a surrogate key violate?

I have following question: "What normal form does a surrogate key violate?" My thought was the 3rd normal form, but I'm not quite sure it's just an assumption i am making. Could someone explain that ...
0
votes
0answers
12 views

Is it proper to make a grand-parent key, a primary key, in its grand-child, in a multi-level identifying relationship?

I'm modeling a DB for a conference ticketing system. In this system attendees are members of an attendee group, which belong to a conference. These relationships are identifying, and therefore FKs ...
0
votes
0answers
29 views

why this FD make 3NF?

Question like this: Consider the relation scheme ABCDEF satisfying the following functional dependencies: BC --> ADEF CD --> B E --> D BC is a key and designated as primary. Explain why the ...
0
votes
1answer
29 views

Dealing with co-dependent not null columns

Say I have a table entities (subclassed by people and organizations tables), where each entry requires a primary_email_id. The entities table looks like this: entities ======== id INT AUTO_INCREMENT ...
3
votes
3answers
415 views

What exactly is overlapping candidate key?

Can some one please explain to me in simple terms what is overlapping candidate key ? What is overlapping as the name suggests? Consider the below relation R(L,M,N,O,P) { M -> O NO -> ...
1
vote
2answers
50 views

Preventing duplicate data when usual normalization only makes sense for some of the records

Background I have two tables, one called issues and the other called status_checks, which both contain (among others) the field comment (VARCHAR). An issue is raised by a user when something needs ...
0
votes
2answers
106 views

How does one know when to stop normalizing?

Alright, so basically I feel that I tend to over-normalize things, and maybe I am doing it at the cost of performance. So, to illuminate on the problem, I have created the following schema to use as ...
1
vote
2answers
94 views

Need help about normalizing database to 3NF

I am currently working on a city travel guide application which let users explore places and plan trip. In the account module, the following functions are to be considered: User can register by ...
1
vote
1answer
132 views

No-SQL Database Design for restaurant app

I've been working with SQL databases all my life and I am now trying to get into the NoSQL world. I am a looking for a piece of advice on whats the best practice in order to achieve this. Suppose I ...
8
votes
1answer
3k views

Generating Invoices and Tracking

Every 2 weeks, the system will generate the invoices for the companies. Company will receive an invoice on the 1st and 16th every month. (It will run via Cron Job every 2 week. It scan through the ...
0
votes
1answer
59 views

Array column vs another table when the relationship is quite small

The Data I am creating a table of cities and their zip codes for the United States. Some zip codes have a list of acceptable cities, as designated by the USPS. For example, the zip code 36613 is ...
1
vote
1answer
48 views

Transforming a relation to 3NF

I'm trying to transform the following relation to 3NF but can't figure it out. The relation is (a student can only have 1 major): STUDENT (StuID, StuName, Major), Primary Key = {StuID} I tried the ...
0
votes
2answers
133 views

One field with multiple values?

I know that what I'm asking can't be done or shouldn't be done, but I really don't know how to do it. This is the problem: 2 tables: - Drivers (id_driver, name, etc...) - Trucks (id_truck, model, ...
0
votes
1answer
480 views

Applying normalization to a relational Database (Access & SQL Server)

This question is pretty specific but I hope it can get answered on here. There is a wide range of information about normalization but I feel what I have read so far isn't as effective as just stating ...
1
vote
1answer
58 views
0
votes
1answer
106 views

A question regarding the performance of normalization

I am sorry this is such a newb question, but it is one thing I am having a difficult time wrapping my mind around, and after an evening spent reading I finally just decided to ask for some ...
0
votes
0answers
31 views

Fourth Normal Form

It's been about ten years since I paid real attention to fourth normal form, and my understanding of multi-value dependencies has seriously waned. How far is this table from 4NF and why? CREATE TABLE ...
1
vote
2answers
92 views

What and How is the ID antipattern?

What is the ID antipattern and why / under which circumstances is it considered an antipattern? The id antipattern is having a unique ID column in each table. The ID is generated for each new ...