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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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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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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160 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 | ...
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56 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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234 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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173 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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2k 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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506 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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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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176 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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271 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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332 views

Are these database tables normalized?

I am developing a webapp for an institute and I designed these tables: Are these tables normalized?
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Database Design - When to use “attributes” rather than additional columns

I'm wrestling with a schema design issue. I'm attempting to determine when I should add another column instead of making it an "attribute". Rather than adding a numerous columns to a table, I ...
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406 views

Does this normalized model for artist music records make sense?

I want to make a database about one artist's music records... CD, Vinyl, Cassette, 8 Track, Singles, Ep, Lp, etc... I believe I have a good normalized model that will achieve my needs, however before ...
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534 views

shoud we normalize user profile table with fields like interests,musics,videos,sports, etc?

I've read in an article about social networking database schema and saw that they've used varchar for those columns that I mentioned in the question title. It's not normalized! Isn't it better to have ...
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Normalization: Should common columns of two tables be pulled out into a third table?

Should I further normalize my current design to eliminate redundancies? I have the following tables: empl: standard user table empl_cat: employee "category" empl_admin_cat: administrative ...
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2k views

Loading multiValued fields into Solr via flat file, and possibly value position preservation in those fields

A hobby web project of mine uses data from many sources, some flat, some highly normalized. My ETL process boils all sources down to one logical table (which is soon to include some multi-valued ...
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41 views

Duplicate records referenced across different databases

I have a table holding 'People' data (about 70K records) that coexists with an 'Address' table so there's one AddressID per every person in the 'People' table. The idea was to centralize the data in ...
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Is the table in 3NF?

I am creating a relational database - a library management system. I want to show an example where I normalize the data from 2NF to 3NF. My example of 2NF looks like The definition of third normal ...
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67 views

Data normalization (from 0NF to 1NF)

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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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 ...
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90 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 ...
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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} ...
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DB Design: Looking for Performance improvement with a Column used in all SQL Queries

I recently got added to a new ASP .NET Project(A web application) .There were recent performance issues with the application, and I am in a team with their current task to Optimize some slow running ...
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Identifying functional dependencies

I'm having trouble understanding the logic in use for identifying functional dependancies. Looking at the sample relation below, I understand fd1 - fd3. But when I look at fd4 and fd5, its logic ...
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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) ...
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Decomposing table into BCNF that preserves dependencies

I have a relation like R(A,B,C) and dependencies like A->B , B->C , A->C I think the relation is in 2NF as candidate key is A. AFAIK when there is only one candidate key then the ...
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Difference in the workload related to data-amount and search option

A couple of days ago I was asked why it is necessary to use the first normal form also for separation of names. We have a table which stores private customers (Name+Surname;Information) and business ...
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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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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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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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Database functional dependency BCNF help

I understand most of BCNF and have been able to complete numerous problems with it, I'm just having trouble applying it to the following situation: R(A,B,C,D,E) FDs: { A->D; BE->A; CD->E } Here's ...
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Difficulty in finding Candidate Keys

I have an homework which should be submitted tomorrow I normaly know normalization concepts but in some questions I have difficulty. How should i normalize this to BCNF? Can you show the steps please? ...
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How to change type from one owner to two different types of owners

I currently have (tables changed): User UserID uniqueidentifier, CompanyID uniqueidentifier, (for future reference) .. more unrelated fields (PK: UserID) UserRating UserID uniqueidentifier, ...
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Functional dependencies and candidate key example [closed]

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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Is It Needed to Normalize of Date Columns

I am designing a small database with relatively small data. The question is about normalization of Datetime columns. The dates of year occured many times and should I create a Days tables with a ...
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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 ...
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628 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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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 ...
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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 ...
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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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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: ...
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435 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, ...
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Move Commonly-Repeated Fields into a new Table

I'm still at the design stage for a new system, and I've noticed there are several places where different types of object share similar fields. In this case, we have customers, offices, warehouses ...
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59 views

Normalise for a very small database?

I am designing a very small database (c. 250 rows). I have a number of datapoints for each record, which under normalization rules, ought to be in separate tables. For instance: Percentages of a ...
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463 views

Same product name with different price in different states

Consider the price of products in the table differs in each state. If the price varies in district I also have to mention it. How can I do this for more than 5 states? product Name Price ...
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218 views

Mobile Phone & Tariffs

I have designed database tables of Mobile Phones & Tariffs. It should support multiple mobile networks, sale type and the related affiliate. Points (for operators) are vary depending on the ...
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444 views

Boyce Codd Normal Form understanding

I have a knotty (at least for me) problem to solve. Normalize, with respect to Boyce Codd NF, the relational scheme E(A, B, C, D, E, F) by assuming that (A, B, C) is the unique candidate key and ...
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Big Size Database and increasing number of users [closed]

Me and my colleagues are using quite big size normalized database. Basically it's used for warehouse management and daily minimum 100 of the user perform data manipulation operations. 80% of the ...