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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What should we do when same column fields occurring multiple time in many tables?

I have more than 20 tables in my database. There are some columns which occur in almost all of the tables. In that case what should I do? Do I put all those columns in every table or is there a better ...
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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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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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55 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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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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unusual relation, binary aspect

I have question very unusual for databases. I’m not a good English speaker, but good English reader :) so for explanation I’ll give you examples. Part1 In MySQL, I have two tables with relations ...
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102 views

SQL Server vs SOLR (Or any document db)

I have my "customer" data in a normalized sql server database. Getting out the customer data in my app is taking too long. This is because I have to go to 10+ tables to get all the data I need. My ...
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52 views

Which one is best solution for future database structure?

I'm working on a big web application. so i need to create user_preference_table it has the marks for every users for each attributes. here attributes are games so in the user_preference_table i need ...
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Storage solution for large number or denormalized records

We currently have a MSSQL server with the data stored in a denormalized format in a single table (per record type) where there can be millions of rows containing many columns in some cases. The ...
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Denormalized tables within OLTP database

My company has a product centered around a fairly normalized mssql server database. At this point we have several reports and a web application that needs the data in a much flatter fashion to ...
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Replace relational database with “poor” design in software product with non-relational DB? [closed]

Edit: This question is about how to deal with many issues that arose from a overall system design, which made parts of the system deviate from common standards. For example, managing everything in the ...
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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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364 views

Best practice database design - user rating tables

I want to create a table to store user ratings of items for collaborative filtering algorithms. So far my table looks like this: IID | UID | Rating i.e. item ID |user id |rating. From ...
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Denormalization Strategies: When is it appropriate to create redundancy for faster querying?

So I sometimes see databases purposely add redundant information for faster querying. I saw that this was mentioned here but I was wondering when would this be better than indexing, or creating a ...
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75 views

Store both a city and its region?

I store various events (such as a search on the site) into a table (in fact I have two tables: one for the event and other (linking to the first) with characteristics of the event). Each city belongs ...
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2answers
66 views

Should I create separate table or have the information as columns in the same table

Sorry for the title but I could not find anything better that could suit my needs. I'm designing the database of a Document Management (Circulation) application. There are two types of documents - A ...
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Should I denormalize lat & lon on area searches?

I run a hobby web site for tabletop gamers. They can search based on postal code in a radius round their location. As I consider adding new countries, my best option seem to be silo'ing the geo ...
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Store millions of rows of denomalized data or some SQL magic?

My DBA experience doesn't go much further than simple storage + retrieval of CMS style data - so this may be a silly question, I don't know! I have a problem whereby I need to lookup or calculate ...
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Database Normalization

If someone could guide me on helping me understand if my results are correct I would appreciate that. Let's say I have the following table: BOOK(BookTitle, AuthorName, BookType, ListPrice, ...
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Denormalizing to speed up inserts

I have a MySQL InnoDb table with approximately 40 million rows and the following columns: param1 (int), param2 (int), param3 (int), geo (char2), value1 (bigint), value2 (bigint) I have an ...
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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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82 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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Will a specific denormalization increase performance in a specific scenario?

Suppose I have a table with fields | a | b | c | d | ... | z | which contains millions of records and which will serve millions of queries a day. And the field z holds the id of some parameter which ...
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Denormalize Design Modification

Our DBA is on medical leave, I am just a developer trying to do my part. Initially, the bean counters were going to use quickbooks. However, after seeing how much time they could save with custom ...
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Are de-normalised tables preferred in any aspect of a project? [closed]

While going through interview , My Interviewer asked me a question about Denormalization of tables and its usage in applications. On guess, I answered, Yes it might be. Being denormalized , you have ...
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Database denormalization: multiple rows into single column. How bad is it? [duplicate]

We have few join-heavy queries to our SQL Server 2008 database and in an attempt to optimize them I thought of having a view that would produce this OrderID Number Traveller 1 102 ...
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Why is my CPU usage increase after setting database to read-only on SQL Server 2008 R2 [closed]

I administrate a reporting database. We run all the de-normalization process on a database DB1 daily, then we copy all the data to an another database DB2 on the same server which is queried by web ...