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.
4
votes
3answers
142 views
Is it recommendable to bypass the definition of data integrity constraints in a relational database?
I’m in a permanent discussion with the developers from the company where I work because they said it is better to get rid of relationship enforcement (via FOREIGN KEY [FK] constraint definitions) in a ...
3
votes
1answer
86 views
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 ...
0
votes
1answer
70 views
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 ...
0
votes
1answer
54 views
Complicated database design
We have a situation in a database design in our company. We are trying to figure out the best way to design the database to store transactional data. I need expert’s advice on the best relational ...
11
votes
1answer
397 views
Modeling a database for Video Game related information with multiple many-to-many relationships
Scenario
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 ...
0
votes
1answer
30 views
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 ...
1
vote
2answers
119 views
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 ...
3
votes
2answers
64 views
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 ...
0
votes
1answer
80 views
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 ...
3
votes
4answers
167 views
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... (...
0
votes
2answers
58 views
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 ...
7
votes
6answers
3k views
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 (...
3
votes
1answer
207 views
How can I prove / disprove If A ↠ BC and A → B then A → C
/ From GATE 2007 IT:
Consider the following implications relating to functional and multi
valued dependencies given below, which may or may not be correct.
A) If A ↠ B and A ↠ C then A → BC
B) ...
4
votes
1answer
259 views
Is splitting a CSV column into a separate table(enforcing 1nf) unnecessary complication?
I had very carefully asked the table designer why he had chosen to create CSV columns in multiple tables.
The designer's answer was that splitting CSV columns into separate tables was unnecessarily ...
-1
votes
0answers
114 views
Help Normalize Movie Database
I'm creating a small movie database and was wondering if someone can let me know if I'm in the right path: The main entities are movies, people, jobs, trailers, and photos.
My main concern is the ...
0
votes
1answer
223 views
Normalization from UNF to 3NF
I keep getting confused trying to normalize this data.
A company makes and sells a product online. There are ten types of Products, each having a code and price.
Their Sales Order department takes ...
0
votes
0answers
23 views
De-Normalized Tables - Querying columns based on a condtion
I've been tasked with developing a report for which much of the information exists in a de-normalized table. The table contains budget information: budget, actual spend, forecasted spend, etc.. Each ...
2
votes
0answers
186 views
Materialized View - vs. New Calculated table for performance [closed]
I have a problem - I'm trying to de-normalize data tables in a data warehouse in preparation for use in the Business Intelligence/ Presentation layer.
By denormalize I mean create a series of joins.
...
2
votes
0answers
48 views
Is there any literature on “re-normalisation” of denormalised data?
I'm involved in a project, the core of which might be generously described as "re-normalisation" of denormalised data. (To be fair, the initial implementation took only the first 90% of the time ...
2
votes
1answer
74 views
Should I split my tables into different tables when all of the data is dependant on the primary key?
For my assignment I have to make a database for my licensing application. I have 12 columns and one column is for the license key. All other columns are data that is related to the license key. The ...
4
votes
4answers
1k views
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 ...
1
vote
0answers
49 views
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 shard)....
2
votes
0answers
43 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
votes
0answers
176 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 ...
1
vote
3answers
229 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 ...
-2
votes
1answer
93 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 |
+------+--------------+
|...
1
vote
1answer
81 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 ...
2
votes
0answers
123 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 ...
0
votes
0answers
167 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 tables,...
2
votes
1answer
377 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 ...
2
votes
2answers
62 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 ...
0
votes
2answers
334 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 ...
-1
votes
1answer
69 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 ...
3
votes
2answers
364 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 ...
5
votes
3answers
1k 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 ...
0
votes
3answers
614 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 ...
2
votes
2answers
782 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 ...
1
vote
1answer
73 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 view?...
0
votes
0answers
130 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 ...
0
votes
2answers
91 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 ...
1
vote
1answer
43 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 ...
8
votes
4answers
430 views
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 ...
4
votes
2answers
326 views
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, ...
2
votes
0answers
81 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 ...
1
vote
0answers
221 views
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 relation ...
1
vote
1answer
125 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 - ...
1
vote
1answer
91 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
votes
1answer
64 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 ...
0
votes
1answer
189 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 ...
1
vote
1answer
457 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 ...
