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 to convert this relation to 2NF?

In my Entity Relationship Diagram, an entity type TEACHER had a relationship of TEACH with another entity type called CLASS. CLASS was a week entity type of TEACHER,so when mapping to a Relational ...
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17 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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56 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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37 views

Problem with reaching second normal form in a database

I'm currently taking an Databases/Database server course as a part of my education, and for this week we have been assigned a simple project to complete. I'm facing a problem regarding normalization. ...
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33 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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23 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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51 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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47 views

Maximum normalization

I have been studying the normal forms rules to guide me with database design and data storage, the problem I am having is that once I optimize for the first normal form (1NF), I figured I may well ...
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88 views

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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19 views

Lossy Decomposition meaning

Suppose I have a relation R=(A,B,C,D) and I decompose it into: R1=(A,B,C) R2=(A,D) then if it is said that the decomposition is lossy,then what is the meaning of that statement?I have an ...
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84 views

Normalisation of practise database [closed]

I am a newbie to database design, and I'm a bit confused about how to create a database with minimum redundancy. Suppose I have a table abc with repetition of data in it and no two rows are same. Now ...
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107 views

Can somebody check this normalisation workings i think i am missing a step or a dependency somewhere

given these two tables: and: I need to first list them as an un-normalised structure(s) then i need to identify the functional dependencies/primary keys. Once i have done this i must represent ...
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104 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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20 views

Normalise the database, struggling to understand how i can normalise this

Cross post warning: I recently found dba.stack exchange so i thought it would be better to post there: ...
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57 views

Functional dependencies and candidate key example

Hi there I'm still learning for my examination and I got this exercise: A table is given: F-Name, F-Nation, Team-Name, Team-Nation ...
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4answers
91 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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136 views

Normalizing data to 3NF

I need some help with normalization. Here is the data in 0NF : **HOSPITAL SERVICES (date_hospitalization , id_patient , id_doctor , name , surname , PIN, duration_of_hospitalization , ...
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141 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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96 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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2answers
47 views

Best design for a many:many relationship issue

We have three types of entity, each with their own table: table:A(a_id), table:B(b_id), table:C(c_id) Each of these entities can have any number of email addresses and linked Twitter accounts. ...
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34 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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25 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 | ...
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101 views

Decomposition of a relation to 2NF and 3NF

I am trying to solve this example, but for now I can't. Can somebody show me, step by step how to decompose this to 2NF and then to 3NF? R = {ABCDEF, ABC -> EF, B -> E, E -> D} key of this ...
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33 views

Decomposition into BCNF where an attribute appears in multiple functional dependencies

I am trying to decompose my relation: R = (A, B, C, D, E) with Functional Dependencies F = {D -> BC, E -> B, A -> B, B -> D} The problem is that D appears in two dependencies and in ...
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59 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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66 views

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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24 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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52 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
127 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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1answer
81 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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38 views

3NF decomposition

Can anyone tell me how and/or why I'm getting stuck here? I have scouted around on the web for examples of 2NF and 3NF decompositions and they all seem to make more sense than the one I'm working on. ...
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56 views

Figuring out determinants when converting table into 1NF form

I have to figure out the determinants in the region for the following table. St ID L Name F Name Phone No St Lic Lic No Ticket# Date Code Fine 38249 Brown Thomas 111-7804 ...
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1answer
98 views

To normalize or not to normalizde? (10 fields)

I'm helping someone to design a database and for a specific case I'm not sure. I have 10 fields - this will never change - that will always be filled and used in every query that could be coming up. ...
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23 views

How to find a projection on the functional dependency?

I have below dependencies on attribute PUT: P -> QR T -> WV R -> UV V -> P Now how to find a projection on the above functional dependencies? I am trying to find a article which can ...
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147 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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52 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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130 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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74 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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26 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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105 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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100 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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120 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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100 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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76 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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628 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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220 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
77 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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85 views

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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3answers
162 views

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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2answers
797 views

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 ...