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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Normalization for postal addresses in US (address, county, city, state, zipcode)?

I've been trying to understand for the last few years which way is good for storing addresses. I've been getting "normalize all the way" but also "denormalize as much as you can" and I just cannot get ...
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Database sharding, denormalization and synchronization

In sharding, it is advisable to follow a share nothing, shard everything approach. Essentially, this translates to: data that are to be used together are to be stored together (i.e. in a single ...
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39 views

How To Manage Random Data Without Repitition?

We have a database design problem of a Learning System. Please can somebody help us ? These are the requirements : A person can register for a module which has "n" number of questions. The person ...
2
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0answers
50 views

Denormalization vs Cached Data [closed]

I'm in a dilemma about denormalization of the database vs. caching the joint query results of the database. We have 2 tables. Let's say A and B. A may have many of Bs but B can be belong to only one ...
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2answers
38 views

Include logical key on each table vs. join

I'm designing a database that is used to track an inventory item through its lifecycle. I'm currently relating my tables using the previous lifecycle event's ID (for example, a shipment contains the ...
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1answer
52 views

Is a normalized MYSQL DB faster than one organized with comma strings?

I've always used databases with comma-separated id strings, something like +------+--------------+ | id | users | +------+--------------+ |1 |2,4,5,6,12 | +------+--------------+ ...
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1answer
37 views

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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47 views

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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44 views

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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1answer
79 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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37 views

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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2answers
60 views

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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1answer
142 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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1answer
55 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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0answers
26 views

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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2answers
211 views

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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3answers
716 views

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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3answers
296 views

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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2answers
414 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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1answer
43 views

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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81 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
70 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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1answer
38 views

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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4answers
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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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2answers
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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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0answers
70 views

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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1answer
87 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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1answer
83 views

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 ...
2
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1answer
58 views

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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1answer
175 views

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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1answer
371 views

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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2answers
309 views

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 ...