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.

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To normalize or not to normalize for few distinct values

Assuming in a Postgres database, you have a table called party, which can have less than 5 well-defined party_types such as 'Person' or 'Organization'. Would you store the party_type in the party ...
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721 views

Normalization: 'zip code' as a primary key

I've seen frequently that you should not have all address fields (zip, street, city, state, country, etc) in the same table as your user info table (pk_id, name, email... ). This would be in ...
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405 views

Is this table in 3NF?

I have a table person with attributes: id name city state country id is the primary key. Is this table in 3NF? If 1000 people live in same city it seems redundant to store the same data for state, ...
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60 views

How to design tables such that a person can work for many companies? [closed]

Database design such that a person can work for many companies?
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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 ...
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766 views

History table design for supertype/subtype

I'm designing an asset management database that tracks IT hardware. I decided to use a supertype/subtype design. I'm at a point where I want to track history of changes for devices. I wanted to use a ...
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274 views

Query regarding normalization of the relations

I am given a case study of Event Management to develop an ER model and based on it its normalization forms and relational schema. Now i have developed my ER Model based on the SRS that i have ...
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84 views

Users Characteristics

I'm really battling an issue where I have a Users table that has a growing number of user characteristics (regligion, smoking preferences, etc). The strategy I've used thus far has been to add a ...
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589 views

Complex query with multiple normalized fields

We have a fairly simple table structure, but with a LOT of fields per table (talking 40+). This data is initially produced in plain-text, user-readable tables, but then it is translated into ...
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98 views

Index optimization on a view using a full outer join

Table structure: Foo FooChild Bar --- -------- --- ID ID ID Date FooID Date ...
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57 views

Building dependence between regional data (Street -> City -> PostalCode -> Country)

I'm in the process of designing a database to contain regional data to be used inside a CRM system. So, a user suspects that things like the city or country are automatically filled (or maybe just ...
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1k views

Functional Dependencies and Normal Forms

I'm trying to grasp the concepts of functional dependencies and normal forms, specifically first (1NF), second (2NF), and third (3NF) normal forms. The link here was extremely helpful in deciding the ...
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305 views

Refactoring/normalization - but almost empty table

I normalized a legacy DB into this structure: But I'm not sure if it is correctly normalized. I don't feel very comfortable with the almost empty filters table. The requirements A group contains ...
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937 views

Splitting a column to normalized table

I have a de-normalized table as Original De-Normalized Table id text 23 first,second|third,fourth,fifth|sixth I want to normalize the database to create the following tables Table 1: (Split by ...
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249 views

Does this design satisfy 3NF, and can any improvements be made?

Does this design satisfy 3NF, and can any improvements be made? If it does not satisfy 3NF - why? By improvements, I only care if it will seriously affect scalability, efficiency, etc - I'm not ...
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646 views

database normalization 2nf, 3nf

I am doing homework about database normalization. I have to decompose the table into 3nf form showing the steps here is the initial table: ...
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43 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 ...
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56 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 ...
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118 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 ...
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400 views

Does 3NF require 2NF?

I am a bit confused with the definition of 3NF. According to Wikipedia: The third normal form (3NF) is a normal form used in database normalization. 3NF was originally defined by E.F. Codd in ...
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143 views

Is this design in 3NF? Why to choose another design not in 3NF

Having the following entities: Objects, Parts, Subparts and Items, and given the following design restrictions: A Part belongs to one and only one Object. A Subpart belongs to one and only one Part. ...
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82 views

Database Over Normalized [closed]

How can you tell when a database is over normalized? Example: I have a database for employee. These are the following tables involved: User - contains email, password, companyId Profile - ...
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230 views

Can somebody help me normalise this database/check my workings

I am new to database design/normalisation and functional dependencies. I have started a new database class in school this week and we have been given a worksheet that requires the following: This is ...
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4answers
2k views

How to handle table design with variable columns

I have a table design scenario and as a non-DBA type, would like opinions on which is more scaleable. Say you are asked to record information on houses for a metro area, starting with a small ...
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1answer
299 views

Can Anyone please review my database after I did the Normalization ?.Any suggestion is appreciated

User: User_ID,user_name,E-mail Staff: User_ID,Fname,Lname,DOB Student: User_ID fname Lname DOB Lecture: User_ID Admin: User_ID Position ID : P_ID,ROLE_NAME, Staff_position ...
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124 views

Relations, dependencies and normal form

I have some issues in understanding about relations and dependencies. I will show two examples and what I want to know: Assume the relation GTX {G,T,X} with the following dependencies: G,X -> T ...
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128 views

How would I change this relational model to fit a nosql database?

Because of things beyond my control, I have to switch from a relational database to MongoDB for the advertising platform I'm helping to build. I've got a relational schema sketched out, but I'm unsure ...
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Stroring a type of an entry

There is a table estate with numeric fields districtru and districthe (for a name of a district in Russian and Hebrew), which refer to primary keys of the table districts. The districts table has the ...
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109 views

Expanding contractions/number ranges into separate records [closed]

I am planning the migration of a directory of image files plus a FileMaker-database containing the corresponding metadata into an Imagic IMS database (formerly known as ImageAccess). The vendor ...
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160 views

Tick boxes and Dropdown

Have a look at the image below: This is "Plain Buger" item - customer can select sauces and extras with it. There are different sizes for Plain Burger. I need to translate this UI into database ...
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762 views

Confusion in BCNF

I understood all the three normal forms which comes before BCNF but when it comes to the BCNF i am finding it extremely confusing and difficult and over the net also i found no good tutorial on it. ...
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1answer
413 views

General Question on how to setup db's for a social networking site

I am currently responsible for designing the entire database setup for a start up website. It is quite a responsibility and I want to get it right, not only for the site, but for my own experience. ...
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865 views

Multilingual Dictionary Database question

Let's say someone is coding a multilingual dictionary in PHP, and he wants to let people submit both words and definitions in English and Spanish, but wants to track it so they can be filtered. ...
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1answer
96 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 ...
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101 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 ...
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61 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 ...
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59 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 ...
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1answer
181 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 ...
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41 views

Denormalization Strategies: When is it appropriate to create redundancy for faster querying?

So I sometimes see databases purposely add redundant information for faster querying. I saw that this was mentioned here but I was wondering when would this be better than indexing, or creating a ...
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611 views

3NF Decomposition - I'm not sure about this example

I am trying to make sense of an example of 3NF decomposition using the 4-step algorithm mentioned by Ullman here, but I'm not understanding what my lecturer is doing with the last step (or, worse, I'm ...
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1answer
50 views

Is this table in third normal form?

I have a table L(A, B, C). Functional dependencies are: A->B, A->C, B->A, B->C. Is this table in 3nf? My thoughts: A and B are keys of this table. Table is in 3nf if there are no transitive ...
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132 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 ...
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330 views

When normalizing a relational database, should multiple “type” tables be combined into one?

Before making substantial changes to the content, functionality and design of my website (I'll be refactoring everything, almost a complete rewrite), I'm setting up a new PostgreSQL database to hold ...
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113 views

Rules for Decomposition to 2 NF

I am struggling with the concept of 2NF form. Lets say I have a set of functional dependencies for R1(A,B,C,D,E,H,M,K) Where : B -> M,C AB -> D DH -> E H -> K A -> H Whenever I ...
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53 views

Decomposing into 2NF

I'm currently studying normalization. I know how to normalize the data for given unnormalized list. But I found this question in our past papers. I don't know how to answer to it. Q. Decompose ...
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70 views

UK Addresses in 3NF

I am in the process of creating a UK only database which holds information for various sets of people i.e. Staff, Clients etc. The tables for each of these sets of people have an Address, City and ...
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93 views

Given the functional dependencies of a relation is there more then one way to normalize it?

I"m studying normalization and have been reading through descriptions and examples online. One Concept that isn't clear to me is if the process can be automated at any point. I understand that a ...
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1answer
63 views

Need some recommendations on organizing data

I'm new here. This question, to my mind, is allowed by the rules I saw in the "2 minute tour". If I got it wrong, no need for nasty grams. I'll delete if enough people say so. But anyway, I have a ...
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1answer
155 views

Scheme review/Normalization level/query optimization

So I have a relatively complex database I'm designing - basically full in-house accounting setup. In one section I have some concern that I'm over-normalizing; the 'directory' - I'll example the ...
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29 views

Normal form for a relation where the number of tuples having the same value in a column is the same for all the possible values in that column

Is there a normal form for a relation that would permit the following table : id | alpha ---------- 1 | a 1 | b 1 | c 2 | g 2 | u 2 | k . . . n | x n | y n | z But not this table : id | ...