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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Find the functional dependencies that hold in a relation

There is a question in my book that asks the following: Suppose we have relation R ( A ,B ,C ,D ,E ) , with some set of FD’s, and we wish to project those FD’s onto relation S(A, B, C). Give the ...
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42 views

Normilsation - 2NF and 3NF

I've been through several questions and youtube tutorials, i understand that 2NF is removing the partial dependencies and 3NF is the transitive ones, but i can't get my head around how the following ...
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26 views

Seeking help for my ASP Project. (ERD Correction Required)

I am doing this simple ASP project for my uni, just wondering if you can guys direct me or give me some advice. Project Idea is to create a recipe website which will allow users to add recipes and ...
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117 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. ...
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129 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 ...
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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 ...
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176 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 ...
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719 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 ...
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264 views

Best way to create relationship between multiple tables

I have a question about how to best handle a table that would be shared among multiple relationships, but shouldn't really be joined with all these tables. For example, suppose I have a table that has ...
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136 views

Is normalization advisable on transactional data?

I have read a lot of articles about normalized vs denormalized schemas, but I find very little mention of the cost of row insertion. I am considering the impact of converting a 100% denormalized ...
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456 views

How to break table into two without losing performance?

According to http://stackoverflow.com/a/174047/14731, splitting away infrequently-needed columns frees up the cache allowing faster retrieval of the commonly-used columns. I've got a table whose ...
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116 views

Is this SQL schema normalized according to 3NF?

This schema is for a sports statistics/data app Note: Pink background = string/char/varchar Yellow background = int/tinyint Green background = dateTime bold column = PRIMARY key id_* = FOREIGN ...
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97 views

Normalization of Time Series Data

I have a table containing various a/b test experiment performance on a daily basis. The table structure looks something like this: date | experiment | user_count | user_attr | sales ...
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42 views

Photo caption and keyword associations

I am creating a database that references images. Keywords and captions will be part of the metadata. These captions and keywords are not necessarily added to the photos with the intent of facilitating ...
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42 views

Does this break normalization?

I have an order table, and in the order table I have a contact_id. Now, each contact is linked to an account. For my order table, should I have both contact_id and account_id? If I wanted to say, ...
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3k views

Airline reservation system [closed]

I'm making a simple airline reservation system. But I'm not sure about the design decisions I made. Concretely, I'm trying to implement following constraints: each Aircraft can have one or more ...
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342 views

Attempting to identify transitive dependency

Hello I am attempting to identify a transitive dependency in the following diagram. I think that possibly the determinate of "Subtotal" is "Quantity" and "Price Charged" but I'm not sure if "subtotal" ...
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57 views

Design for hierarchical embedded database

The goal is to construct a hierarchical database of Objects having the following format: TypeA -> ObjectA [values, contains ObjectB*, ObjectC*, etc.] TypeB -> ObjectB [values, contains ...
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49 views

How to relate 2 tables to a third when the first 2 tables have a relationship?

For once, I find myself at an utter loss in terms of coming up with a good question title. Consider the three following tables. Each has additional columns, but only the columns relevant to the ...
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119 views

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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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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125 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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231 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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3answers
113 views

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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294 views

Most efficient way to structure segmented data

I am faced with a set of data which I am currently unsure on how to store efficiently. The data in question relates to a calendar which stores information on two different categories of event which ...
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Normalization Question Regarding Types and SubTypes

I'm trying to organize database tables representing something I'll call a report instance that would be related to a specific report for a given execution instance. A one to many relationship exists ...
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Problems in Choosing Foreign Keys :S

I am designing my very first relational database. I am now in the conceptual design, building tables and views, selecting the primary and foreign keys and normalizing everything. But now, I am stock ...
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Am I right about this normalization form?

A given schema R (A,B,C) where A->B, and B->C. a) What normal form is R in? b) If R can be normalized any further please normalize it. My answer for part a) 3NF and b) boyce-codd normal form. Am I ...
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Nullable Fields to Separate Table?

My website has a form page that has radio buttons yes|no corresponding to 7 questions. When the user selects yes, the user needs to specify a value (either a location, name, or medical condition, ...
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41 views

Find the Minimal Basis

Suppose we have relation R ( A ,B ,C ,D ,E ) , with some set of functional dependencies, and we wish to project those functional dependencies onto relation S(A, B, C). Given the functional ...
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35 views

3NF to BCNF without loss of any FD?

Can you provide an example of a relation which is 3NF, but not BCNF; and while breaking the original relation into two (or more) relations, no FD loses?! Tanx.
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Lose some FDs in 2nf normalization?

Suppose we have R=(A,B,C,D) and FDs are {B->C, C->D}. The only candidate key is AB, then A and B are prime; C and D are not prime. B->C breaks the 2NF requirements because is a partial dependency. So ...
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83 views

Decompose table into third normal form

Tables X and Y are given as below : X (A, B, D, E, F, G, H, J) with A and B as primary key Y (K, L, M, N, O, P, Q, R) with K and L as primary key Now we need to decompose these tables into tables ...
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Normalization and multivalued attributes

I am designing a relational database in mySQL - a library management system. I want to show examples of the data in 1NF, 2NF, 3NF, BCNF, etc. My example of 1NF looks something like this 'A relation ...
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Multilingual Article/ Category database design

I wasn't getting any answers over at Programmers and was advised to go over here instead... I wanted to make a design for a multilingual database and after having drawn it up have arrived at 5 ...
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Data-Duplication Vs Data Normalization. Better DB model?

I've 2 tables as follow:- Table UserProfile:- id name age gender phone city state country fb email and UserPoints Table having the following fields user_id activity_date app_point redeem_point ...
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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: ...
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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, ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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Closure set of functional dependency

Can anyone tell me what is the use of finding the closure set of a functional dependency? I know how to find F+ from F but don't know the use of F+.
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How can I maintain old information after an update?

I am having an issue figuring out a solution to not lose old information. For example, customers can place many orders. Let's a customer, Mary, makes her 1st order in 2013. Fast-forward to 2014, ...
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Users_With_Messages Table normal form

I have the following tables in my database: Above these tables (not pictured) is a Users table where the SendingUserId and ReceivingUserId are keyed onto (they are foreign keys). Are these tables ...
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Normalization of irregular relations?

I have two tables in MySQL: The orders table CREATE TABLE `orders` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `transaction_id` varchar(20) COLLATE utf8_unicode_ci DEFAULT NULL, `task_id` ...
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369 views

Airport Database Design guidance required

I am trying to make a generic database for airport management and DBMS would be oracle 11g xe. Since, i am amateur and still learning so i have tried to kept the problem statement simple with limited ...