Questions tagged [denormalization]

Database denormalization is the action of adding redundant data to database for performance optimization. This is the opposite to normalization where data is split into separate tables.

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A clarification about data normalization

I've been a software developer for 8+ years now and I think I have a pretty good grasp of the concepts but as an entirely self-taught developer, I have some unfortunate gaps in proper terminology. ...
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Junction table or denormalize?

I'm using MariaDB. I'm designing a simple application that can send notifications to subscribers for when certain websites they've subscribed to have been updated. A user can be subscribed to several ...
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Should a counter column with frequent update be stored in a separate table?

I have a MySQL/MariaDB database where posts are stored. Each post has some statistical counters such as the number of times the post has been viewed for the current day, the total number of views, ...
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Does combining multiple tables into one table with more than 100 columns improve performance and overall design?

I have 10 tables without any type of foreign key relations between them. All the tables have the same primary key. In this case, "stock_id" is the primary key. All table columns describe a ...
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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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Can I use Azure Data Lake in place of Data Warehouse to separate Compute and Storage of RDBMS analytics [closed]

I am from a telemetry data engineering background and am looking for some help on a use-case I am not familiar with as to whether my proposed architecture is practically feasible in Azure. The use-...
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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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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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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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how to professionally normalize my database - screenshots included

Hello database administrators. I got some excel spreadsheet with data of "my customers" and I'd like to create professionally designed database out of it. Can anyone tell me how this data should be ...
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access database normalization :how to deal book volumes like 1-2 or 3-4 [closed]

my question is about NF1 what is best practice to store book volumes in table . for example mostly it is like bookname = abc volume= 1 ect but some time it is abc volume 1-2.
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Does any MariaDB engine have the option to declaratively or configuratively abstract highly-redundant data?

I have an application which is architected in a "NoSQL" style around one fully denormalized "main table" which currently just holds a primary key and one JSON-valued column. For reasons which are ...
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How to denormalize many-to-many relation without nested select?

I have the following schema: house has many students, student has one house gender has many students, student has one gender game has many students. student has many games For instance, consider ...
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Why is data integrity not possible when using denormalization?

This tutorial says the following: For proponents of denormalization, the thinking is as follows: normalization creates more tables as you proceed towards higher normal forms, but more tables ...
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Table with only one column because of many-to-many relationship?

Right now I have three tables: person, alias, and person_alias. As suggested by the names of tables, one person can have multiple aliases and one alias can be used by many people, and hence I add a ...
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Are updates the only disadvantage of denormalization?

I am trying to understand what are the disadvantages of denormalization. Say that I have the following database (School_has_Student is a denormalized table): I have read that the problems that you ...
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Select records based on earliest date in a linked record

I am a retired teacher working on my first MYSQL database as a personal project; please let me know if I've inadvertently violated conventions. And thank you! The database's domain is fiction stories,...
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Is this a good database design or transition? Normalize to Denormalized for Data Warehousing [closed]

As of now in sql server , we have a data and a series normalized table structure that is connected to a C# web app (Human Resource / Recruiting System) (slightly medium (or small 12,000 rows.) size ...
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Modeling Sellers and Products

I'm trying to model product and seller information. The seller can be either an individual, or a company, or a company with branches (and the product is being sold by a particular branch). Each ...
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Normalizing the Test Table

I'm a web developer looking to leverage more of the power of my RDBMS. I'm currently learning about normalization of data and database design. In the book that I am reading, we started off with one ...
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Normalizing data past initial db design phase

I wanted to poke at everyones brain to better understand when it makes sense to normalize a table that carries redundant data. I recently worked on a project at my startup and really question myself ...
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Storing personal data on an invoice to preserve data integrity

I want to store invoice data like addresses of people. But the problem is addresses can change over time - for example someone will move out and change his address. The problem of storing such data ...
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When is it beneficial to move duplicate data to a reference table?

If there is column with values from some finite set S, for example S = { alive, dead, unknown } for a life_state column in a persons table, when is it beneficial to add a reference table? Options: ...
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Schema For "Other - Add Comment"

Many user forms contain an option for "Other - Add Comment" where the user can provide an item not found in the given list. In other words, the developer sets the list of items. The user must either ...
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Checking if a transitive key dependency is in 3rd normal form

I'm currently trouble determining if one of my schemas is in third normal form. I have a table with columns image_id (A), upload_time (B), uploader_id (C), and image_file (D). A is a key (unique ...
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Storing Procedure Fields That Were Used

I am creating a database for production work (specifically lab testing). Most Work is for production, therefore performed strictly according to the Procedure for that Product. By itself, this is easy ...
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Normalization of database according to the given data

I'm creating new database based on existing database, performing some normalization. Here is the table containing multiple information, it's basically for booking trips etc I've divided all the info ...
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How to design database tables using normalization in better manner in SQL?

I have designed my tables in below manner. Countries Table:- PkId --- + Country Name --- + StatusFlag 1 | India | L 2 | China | L 3 | Sri Lanka | L ...
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Is combining independent tables called normalisation?

So, at workplace, we currently store our audit logs in different tables, depending on what it is e.g. login/access info, configuration changes, etc. These are all independent data with no foreign ...
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How can I optimize this query over this logging table?

I am trying to optimize a table layout for a table that logs events. The log table contains three relevant columns: Timestamp, ItemId, LocationId Each row means that at a given time, a certain item ...
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Is this really in 3nf?

I cannot comment on https://stackoverflow.com/questions/8437957/difference-between-3nf-and-bcnf-in-simple-terms-must-be-able-to-explain-to-an-8, so I have to post my question here. It is about the ...
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Redundant FK on parent relationship is denormalization?

Let's say I have this database client | id | status | sale | id | client_id | date | sale_item | id | sale_id | *client_id* | The *client_id* column is redundant, because we can JOIN and get ...
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Two primary keys but not a composite, what is this sort of relationship called?

I am integrating employee/position data with another system. The first system is HR. It has an Employee table and a Positions table. The second system tracks office space and tracks who the office ...
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PostgreSQL multidimensional array - ok to use or misdesign in this case?

I have a table called listings. For each listing, the user can upload 5 images. In the table listings, I have a multidimensional array images text[][]. Each multidimensional element will hold [ a ...
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ALTER TABLE online by keeping data as BLOBs

Could you please explain me how extreme de-normalization (store the value as a serialized blob will help to ALTER TABLE online? source Additionally, it's crucial to be able to change the schema: ...
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Database normalization vs several dozen joins [closed]

Using PostgreSQL I have a few tables that are about 22,000 records and about 275 columns. These tables are actually reports. There are about 25 sections in each report containing anywhere from 4-12 ...
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Duplicate data or Relationships?

Given two tables: Product int id int operator_id string name string description int price Operator int id string logo_path string tos_path int tax_number I need to call multiple ...
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Similar data with fields redundant in one table

I need four different plans to be stored in one or more tables. All four plans share the fields however some plans have extra fields. All plans fit into the plans-table: PLANS(id, provider_id, ...
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Normalization vs denormalization for these kind of data?

I'm using Firebase realtime database (NoSQL), And trying to figure out the best database design for my data. My data is primarily about discounts, each affiliator introduces a number of discount ...
10 votes
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Integrity constraints in a relational database - should we overlook them?

I’m in a permanent discussion with the developers of the company where I work because they say it is better to get rid of relationship enforcement (via FOREIGN KEY constraint definitions) in a ...
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Do I have to (sometimes) sacrifice normalization for data integrity?

I often come up against the following challenge, and end up de-normalizing my table design in order to enforce data integrity. I would be interested to hear if there is a different way of modelling ...
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How to prevent Performance issue & going for Denormalization

We are planning to do an e-commerce shopping site with PHP-MYSQL combination. I read in almost every link related to Normalization & Denormalization : Normalize until it hurts, denormalize until ...
16 votes
1 answer
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Designing a database for a video game business domain with multiple many-to-many relationships

I am relatively new to database design, and I decided to make my own hypothetical database for practice. However, I am having trouble modeling and normalizing it, as I esteem that there are numerous ...
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Checking for BCNF in a relational database through FDs?

Okay so I know that for BCNF, when listing all non-trivial FD's that everything to the left has to be a candidate key. So I have this relation: Person(Id, TFN, Name, Phone) Where Id and TFN(Like ...
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Need advice on database normalization

I am working on a basic blood bank database on Oracle. I would like to create a completely basic normalized table and then I will add more details to it. I have done it to the 2NF and I will further ...
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Is it a good approach to duplicate data in a database?

I have a program that needs to store traceroutes (among other data). Here is a diagram that depicts the business scenario: My use case right now is to store the traceroutes using the following ...
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contradiction of 3rd normal form on address table

I have an Address table and its columns are address_id, address_1, address_2, city, state, country, pin code .Its primary key is address_id . According to 3rd normal form no non-key attribute should ...
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Should I Denormalize Tables To Avoid Joins?

I'm in the process of developing a web application, and need some help with some basic db design. Currently, I am unsure of the following three tables: ### User ### - Id - DetailId - etc... (About ...
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should I denormalize for user profiles?

Assuming the choice is to stay with relational model, how are tables structured in the case of large User profiles? All the examples I see consider only simple cases, such as a "profile" containing ...
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Possible benefits of storing multiple values in one field of one row instead of as separate rows

During our last weekly meeting, a person that has no background experience in Database Administration brought up this question: "Would there be a scenario that justifies storing data in-line (...