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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How can I normalize this database?

I've got legacy ecommerce database, which is awfully designed and I need to move all products from it to new solution. But I stuck with how product properties stored. So it basically has tens of ...
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Database Normalization help needed

I have been trying to find the normal forms and bcnf for a few database relations, can anyone help me and tell me if im not the right track, if not tell me where im going wrong In the first questions ...
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27 views

Effectively modelling extended classes

I have 3 different types of content for a website, 'Article', 'Video', 'Review'. Each of those three types of content contain common fields and type specific fields. For this, I have created the ...
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92 views

Normalise an expenditure table in a budget database [closed]

We have a budget database that stores expenditure items per budget. There are over 100 expenditure items each having common attributes: Amount, Frequency, Comment. The table will have over 300 ...
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3answers
373 views

Database design for bookmark system

I am creating a bookmark system where people can save their bookmarks. Each user has its own personal page with bookmarks. A bookmark should have atleast one tag and max five. Each user can create ...
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2answers
154 views

Normalizing nearly identical tables

Background I'm managing a relatively small database project in which we are adding support for reporting involving status updates for items in out product table. I was bit thrown into this and I've ...
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1answer
697 views

Two-column foreign key constraint only when third column is NOT NULL

Given the following tables: CREATE TABLE verified_name ( id SERIAL PRIMARY KEY, name TEXT NOT NULL, email TEXT NOT NULL, UNIQUE (name, email) ); CREATE ...
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3answers
439 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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141 views

How to normalize data en-masse?

Goal: Extract address fields from a users table into a separate addresses table linked by foreign key. I have created the structure below, and have millions of rows to deal with. I need to do this ...
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Separate archive tables or soft delete for inventory database

I'm building an inventory database that tracks computer equipment and other hardware devices. At some point in any device's life it is retired and gets archived. After it becomes archived it needs to ...
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1answer
146 views

If all variables are a subset of the candidate key, is the database design 5NF?

I have a table called LogMessages, which has the following columns: Level A numeric value which represents Trace, Debug, Info, Warning, Error or Fatal Time A UTC time Message Foreign key to a ...
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54 views

Is this table designed properly

I am trying to model the process of where one co-worker enters a statement of their proposed work procedure and another co-worker commenting and approving the statement. Currently I have one table as ...
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155 views

Should I extract / normalize the mailing address despite requirements limiting number / type of addresses?

I currently am working on a contacts application (similar to Outlook contacts combined with eVites and LinkedIn). The requirements for the application are to limit the addresses (and phone / email ...
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27 views

Good idea to include summary of frequently accessed data from another foreign-keyed table?

Sorry for poor title, I'll try to explain it in more detail here. I have an application that often gets a row from table A, then looks up a column from that in a foreign key mapping table (table B), ...
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1answer
1k views

School database design

I am trying to design a database management system with my PHP and intermediate MySQL knowledge, keeping normalization in mind. These are the assumptions: The school has many students from grade 1 ...
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129 views

Simple table normalisation

In raw form, I have data with 2 columns: skills in welsh and stats for that skill. For storing these information in a database, would it be best to combine the stats with the categories, or split ...
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2answers
149 views

Design consideration regarding state handling: how to store multiple, variable states for one entity [closed]

First I have to admit that I'm not a database professional neither are my colleagues. For a new project my colleagues and me came to a design question we couldn't really solve easily. And all the ...
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2answers
115 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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1answer
140 views

store country name or country id [closed]

I am designing a database layout for a site. Agents registering on the site will have to enter their address including the country. Later I will build a dashboard where you would be able to ...
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1k views

Duplicate column for faster queries?

The title doesn't make too much sense, but I couldn't think a better title for this problem. I have the following tables Projects id name Customers id id_project name Payments id ...
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2answers
582 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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433 views

3NF decomposition + database normalization

I am studying for a test and would like to know if I am on the right track to get the following into 3NF with minimal number of keys for R: Given relation R(A,B,C,D,E,F,G) and the functional ...
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1answer
543 views

MySQL database normalization 3NF

I have homework where I need to create simple web interface and a DB normalized to 3NF. I've chosen ISP client selfcare as my database purpose. Web interface is no problem, the normalized DB is. After ...
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3answers
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First Normal Form, why is it good and how does it reduce redundancy

I asked a similar question on SO and was advised to ask the type of question here. This is for a course on relational databases. A sample problem asks "how come every table in a relational database ...
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1answer
351 views

UNF to 3NF is this relation workable?

I've inherited a flat table of data consisting of around 2 million records. Looking at the data its already in 1NF, i'd like to get this into 3NF. The data is Australian so suburb can't determine ...
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2answers
102 views

3rd Normal Form violation?

I've got a photo review type of application, where the customer wants to have an option for the user to flag issues with the photos. So, for instance, a photo could be tagged as "fuzzy," "grainy," or ...
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Questions regarding second normal form

I understand that in order to fulfill 2.NF, attributes must not be dependent on part of the key. Now, the question is, let's say we have a relation R with a set of attributes {A,B,C,D,E,F,G,H,I,J,K} ...
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Database design for conditional detail table

I have an expense management system for monthly expenses. Expenses are of two types: one-time monthly expenses, and daily expenses for each day of month. I have created the following tables: ...
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Decomposition of a relation to 2NF then to 3NF

I'm currently studying for my exams and the trouble I am having is how to decompose a relation R with given functional dependencies into 2NF then 3NF. For example for the following R and functional ...
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MySQL Database Normalization Foreign Keys. One to Many relationship. With Diagram

Here is my database design. I've been doing a lot of reading and still don't really know what I'm doing. Hoping you guys had tips! My DB will have millions of entries. Many "People" rows will have ...
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789 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. ...
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6answers
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Is normalization process needed?

Well after learning DBMS as a subject i got so many questions in mind. Normalization is one of them. As i learnt it there was a lot more confusion and i found that whatever we do in normalization ...
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Column partially determining accepted values of another column, should be somehow normalized?

I have a table that describes a set of properties (yes it's metadata, in this case there's a valid reason to have it in the database); among other things I tell the type of the data that can be ...
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3answers
107 views

Normalization/normal forms - May a field describe an other field?

Like this: CREATE TABLE persons( id serial8 NOT NULL PRIMARY KEY, name varchar, -- A lot of other fields date_of_birth timestamp with time zone, date_of_birth_precision ...
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How can a database be normalized when an optional field causes denormalization?

Suppose you have a warehouse full of widgets. Each widget in the warehouse is stored in a specific identifiable location within the warehouse. You might have a schema which looks like this: A ...
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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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Why is dynamic pivoting not supported?

TL;DR What is the reason that in 2013 we still can't define a VIEW that displays some pivoted data with a dynamic column set. TL;DR/2 Is pivoting data a denormalization technique? First: Not going ...
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Challenge: Build MySQL table that's not in first normal form [closed]

I have read numerous books and articles about database design and SQL in which it is said that a database should be in first normal form (1NF). (Some then go on to describe situations in which it may ...
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321 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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Is there a tool to check if my database is normalized to the third normal form?

I learned about normalization recently, and understand how important it is when implementing a new schema. How can I check if my database is 2NF or 3NF compliant ? Manual review is a sure option, ...
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715 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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163 views

Approach to Analyzing Database Requirements

When presented with requirements for a database driven system, I always find it useful to imagine a world with no computers, where data records were kept in filing cabinets and data was collected by ...
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291 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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90 views

BCNF when no keys are available

I have a problem understanding a particular case of BCNF. Let's suppose that we have a relation R(B, C, D) with df:{C->D}. Is my relation in BCNF and if yes why??? Is C considered as superkey?
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382 views

Record with variable number of columns?

I am trying to model a cable mapping for devices. Each device has multiple cards, and each of those cards has multiple ports. Since both the number of cards and ports vary, I am confused on how to ...
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Unable to decompose this relation to BCNF

I have a relation R = { A, B, C, D, E, F, G, H, I } And functional dependencies F ={ ABC -> DE E -> C AB -> F C -> G F -> H H -> IJ F -> B } I am able to do simple BCNF ...
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Best relational database structure for this data

I'm in the process of creating a database scheme for the following scenario: There are users Users have roles (such as "Developer" or "CEO") Roles have applications (such as "Topdesk") Applications ...
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1answer
242 views

Does my design adhere to 3NF?

I created this schema with OpenOffice. Does this design adhere to 3NF ? (A relationship link between Equipment and Supplier_Equipment , Customer and Membership should be created but OpenOffice ...
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3answers
1k views

Simple scenario needs to go from Unnormalized Data to 3NF - Review Please

NOTE: The Question has been updated. View Edit Revisions to view original question. The scenario. An animal charity that at the moment, track their establishment's costs via a spreadsheet like so: ...
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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 ...