Questions tagged [normalization]
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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table organization with data that will never change
for reference, almost all my DB experience is with mongodb and this is my first postgres project.
I'm storing data updates from decentralized finance crypto pools.
The data structure I'm exploring is ...
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26 views
How do I identify functional dependencies and normalize a table based on the attributes?
I'm having trouble identifying the combination of attributes which make up Functional Dependencies(FDs) of a particular table. While I understand how Normalization process works when given the FDs, I'...
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How to model one-To-Many where multiple entities could be one the one side of relationship
In my domain i have Muliple Entities that can have a one to Many with an entity named Component
<Car (1)> <---------> <Component ()>
<Bike (1)> <---------> <...
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Best Suitable Database Structure in Oracle for Multiple Questions and Answers
I am building a Form in which User Select Different types of Protocol
Select Protocol:
Protocol 1
Protocol 2
Protocol 3
If user select Protocol 1 Then Number of Disease (Disease 1, Disease 2) Will ...
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Help converting the following entity and its attributes to 1F, 2F, and 3F through normalisation
I am learning about normalisation and would really appreciate it if someone can walk me through the process of putting the following entity and its attributes through all 3 levels of normalisation (1F,...
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Does relational design discourage splitting tables unnecessarily?
It's been a long time since I studied relational design, but I had a vague memory that it encourages not splitting a table unnecessarily. For instance, given the functional dependencies
K -> A
K -&...
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2answers
50 views
How to normalize a table with multiple cells that have multiple values?
So I'm doing a task where I take a massive list (30,000+) of movies on Wikipedia that have multiple columns (such as the films name, the genre, the cast, the plot etc.) and upload it into ...
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Is it allowed to for two tables to have two types of relationships between them? [duplicate]
I have been going back and forth working with relational and no-sql databases for some time now and my questions may be the result of mixing the way of thinking about how to approach a problem.
So ...
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SQL: shopping cart design for a multi vendor marketplace [closed]
I'm working on a B2B marketplace where users can order from different suppliers/vendors. The following image is a sample from my original schema to clarify the cart functionality.
The cart_item table ...
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2answers
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Is it possible to store historical configuration settings for each row of data without cramming all the configuration settings into each row of data?
For background: I was recently hired as a database engineer for a water treatment company. We deploy water treatment machines to sites across the country, and the machines treat water and send ...
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Normalization using DENSE_RANK and LAST_INSERT_ID
db-fiddle
I have created a table called orders (orderId, customersId) and a table called orderDetails (orderId, productId). My goal is to denormalize a table called temp which is like
scanId, ...
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1answer
55 views
How do I prove this relation is in the `3FN`?
Consider the relation R(A,B,C,D,E) and the set of functional dependencies F={A->D,D->C,BC->AE}
I need to prove this relation is in the 3FN, however I don't think it is; in fact, I don't even ...
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2answers
43 views
MySQL Insert Values Into Normalized Relational Database (multiple tables) at the same time
I have normalised my database to 4NF. How do I now insert values at the same time when records have been split into multiple tables? most of the child tables reference their parent table CUSTOMER ...
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1answer
29 views
If `AB->C` and `A->B` , `A->C`?
I'm new to databases, is this true? if so, how can we deduce that?
I don't know how to use the properties to get an answer, could you help>
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How can I design Person table in MySQL?
I have two person type: Users and Clients.
Users can login the panel but clients can't login the panel.
My current database: (but this design not good for me. I need to connect these tables to the ...
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2answers
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Is this the proper way to integrate normalization? [closed]
I'm trying to wrap my head around normalization.
Is this the proper way to create a database with this data? How much more effective is it to use a foreign key instead of just repeating AAPL for ...
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1answer
58 views
How can I design address table?
Hello I need designing addresses table. I designed it but I didn't like it very much.
My needs:
I have customers and users (admins). I have addresses for customers and users. We need design in ...
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1answer
46 views
How can I design Address table with different types?
I have a Address table and different address types like Personal and Corporate. I design a table but I think is breaking normalization rules. How can I improve this design?
My design:
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What should be the schema of the database if the parent table is being referenced in more than one child table?
I have three entities in my database: Category, SubCategory, and Product. Now the thing is SubCategory is dependent on Category, whereas Product can be dependent on SubCategory or directly either on ...
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259 views
BCNF decomposition which generates redundant relations (as for 3NF)
Sometimes the 3NF synthesis decomposition algorithm (such as the one described here p.4) generates redundant relations, where all attributes of some R_i already appear in another R_j. The algorithm is ...
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1answer
37 views
Database scheme design for complex movie system
I'm creating a complex app for cinemas including frontend and reservation system. I struggle with a DB scheme and this is a worst part for me, I was never good in designing DB's.
Easily said it's a ...
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2answers
75 views
Database normalization for sensor data
I'm working on the backend of a quality evaluation tool. And I hit a the limit of too many columns.
SQLSTATE[HY000]: General error: 1005 Can't create table xxx.xxx (errno: 185 "Too many columns&...
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3answers
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How do I ensure I have split my tables without loss of data?
This is w.r.t Database Normalisation, when I have a redundant table that causes anomalies, I would want to consider splitting it in smaller tables as per the NF rules.
BUT
Say I split a big table into ...
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1answer
31 views
Meaning of “Dependency” in Relation to Elementary DB Normalization
In trying to figure out why the following table definitions from a textbook exercise about nurses in hospital wards is not in 2NF:
Ward (WName, Location, WType)
Ward-Nurse (WName(fk), NurseID, ...
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1answer
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JSON vs Record/Struct type in a DB
It seems like some databases have implement a Record/Struct type and others have implemented a Json/Jsonb type to handle nested data structures. A few examples being:
BigQuery Struct
CockroachDB ...
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1answer
71 views
database design - table with multiple nullable foreign keys
Context:
I have 3 unrelated entities (tables) Entity1, Entity2 and Entity3
I have a table called Operation, which can have multiple targets.
A target for an operation can be Entity1, Entity2 or ...
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How can a 'Request' store a 'Result' code and its associated 'Error' code and still enforce the relationship between Result and Error?
I'm an application developer creating the database structure to represent a flat file message format. I'd like to ask the collective knowledge the best/correct way to represent the following scenario:...
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2answers
97 views
Postgres normalize human name string
Is there some function to normalize name string:
select normalize('R.C. Bray')
'R. C. Bray'
Or the opposite direction?
The simple replace('. ', '.') or replace('.', '. ') is wrong and may be ...
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1answer
23 views
More tables or More records performance wise
i am into a scenario that upon looking at the our project database contains Identical tables with the schema described below:
id
url
region_1
region_2
region_3
region_4
date_created
My ...
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0answers
25 views
Is this definition of 5NF right?
From what I've gathered from my textbook, 5NF doesn't allow lossy decomposition, so that when we join tables that are in 5NF, no spurious tuples are generated.
The definition in my book states that:
&...
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1answer
96 views
Most efficient table structure for multi-tenant database
I have a conventional relational database (mySQL) with several entities stored in their own table. Three examples are images, events and organisations.
We are making a change to the way our site works ...
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Can a table be un-normalizable or am I misunderstanding the theory
I was considering normalizing a flat table (SQLite if its relevant) I'd been working with in a small personal project and it just didn't seem to make sense.
Consider an example table like below. Each ...
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1answer
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Relational-JSON overlapping with association [closed]
I have a composed class called sensor that is linked to a main class Node such that:
class node is linked with another node to make a communication that produce an event
class sensor can as well ...
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3answers
42 views
Is storing data that can be inferred go against data normalization?
To simplify lets say I have two tables PROJECTS and JOBS. A user creates a project and runs 1 or more jobs using a project.
So it would possible look something like this:
PROJECTS
[PK] project_id
...
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1answer
76 views
How do foreign keys affect partial and transitive dependencies (databases)
I'm struggling to work out how foreign keys can affect partial and transitive dependencies when normalising databases.
I have multiple tables, two of which are job offer and accepted job.
in job offer,...
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1answer
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Table normalisation and empty values [duplicate]
Here are two ways I can optimise mapping of a text field with several other attributes to question and answer. First approach is, creating a map table with both question_id and answer_id in which ...
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1answer
34 views
Refactoring out a boolean column [closed]
I have a Pets table (cats, dogs, you name it) with over a million records. For simplicity sake, it looks like the following:
Pets
Field Type Null Key
id int(11) NO ...
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1answer
43 views
Database Normalization Advice [closed]
I have database for multi store application. So, I have 3 type of user thats Admin, Customer, Merchant and I have 3 table for users. User table, Customer table, Merchant table.
User Table;
id
...
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1answer
185 views
Weak Entities + Partial Keys + 2NF [closed]
I'm a bit confused on the concept of weak entities and normalization and couldn't find any answers online. I know that generally weak entities have a partial key to uniquely identify its own records ...
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1answer
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Celebrities database with multiple parent categories and children categories? [duplicate]
I am creating a React/Laravel web application that will allow the user to search and navigate through celebrities based on their 'categories'. I have set up a Categories table using MySQL like so:
*...
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1answer
22 views
Where can I get a proper dataset for performing Normalization techniques? [closed]
I'm new to databases and I just started with learning different techniques of Data Warehousing. I was given an assignment to perform Normalization techniques on a dataset of at least 1000 rows with ...
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1answer
24 views
Is it correct way having status or Summary columns in parent table or should choose another precedure?
My Parent Table is "Jobs" table, and there is child table that records Job's actions named "JobActions" as below:
Jobs (JobId, JobType, CurrentStage, AssignedTo)
JobActions (JobActionId, JobId, ...
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1answer
179 views
Need Help With BCNF Decomposition Problem
I'll try and keep it as quick and concise as I can: I'm currently a novice developer who's super eager to learn Database Normalization and Optimization so I can up my skill in Full-Stack development, ...
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2answers
32 views
Relationship normalization in SQL Server
I want to know should I remove PersonTypeId from Persons table or is it a good idea to have it in there?
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2answers
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Alternatives to storing a record with exactly n multiple foreign keys from the same foreign table, where the relationships can't be repeated
Say there are entities called singulars, and entities called relationships.
It takes exactly two singulars to make up a relationships entity.
That pair of singulars can't be repeated elsewhere in ...
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Can there exist Tables with no Non-Prime Attributes? If so, are they always normalised to 3NF?
Can there exist a table with no non-prime attributes?
Here is an example of a table which I believe has no non-prime attributes:
I came to this conclusion because the list of attributes in the ...
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2answers
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Does one of the normal forms require separation of repeating clusters of values into another table?
Should the repeating values in the "Sales" table below be separated out into a second table as part of the process of database normalization? Note that none of the values are functionally dependent on ...
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2answers
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Normalization Excercise Clarification
Have a bit of confusion regarding a normalization from 1NF to BCNF. The teacher gave us this excercise to illustrate a normalisation all the way up to BCNF. I think I have found a problem with the ...
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1answer
144 views
Database Design: Normalization and NULL values
I have normalized my table from 0NF to 2NF (hopefully correct).
How do I now go from 2NF to 3NF?
Also, ResponseToTransactionId is a recursive foreign key that will contain NULL values a lot of the ...
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SKU and Price on product that have multiple attributes
Currently, my Inventory system is writing products data like this:
T-Shirt Gildan -> blue, L, short -> stock: 140 -> price: $40
T-Shirt Gildan -> blue, XL, short -> stock: 0 -> price: $45
T-Shirt ...
