Tagged Questions
2
votes
1answer
70 views
Database design decisions
I trying to create an efficient and scalable data model for an application that I am writing. I am coming to a common problem as far as the design goes, the example listed below exemplifies my problem ...
13
votes
10answers
4k views
Should not OLAP database be denormalized for reading performance?
I always thought that databases should be denormalized for reading, as it is done for OLAP database design, and not exaggerated much further 3NF for OLTP design.
PerformanceDBA in various posts, ...
12
votes
6answers
6k views
A good database modeling tool for PostgreSQL? [closed]
PostgreSQL comes with the excellent pgAdmin-tool for managing the database but lacks GUI data-modeling utility?
I found this list: http://www.databaseanswers.org/modelling_tools.htm
but don't have ...
0
votes
1answer
46 views
Dynamic Data inside MongoDB
I'm making dynamic data storage, which it was in relational data base as:
form -> field
form -> form_data
field -> field_data
form_data -> filed_data
and field data contains field_id, ...
0
votes
0answers
21 views
Mapping a hierarchy into a relational database model
I am currently diving a bit deeper into database modeling. I have a very simple hierarchy as the following one:
Company -> Department -> Team -> Employee
What I am asking myself is the following: I ...
3
votes
3answers
119 views
Database Schema for User Tagging using Nested Set/Adjacency List
I have seen many posts on building database schemas for object tagging (such as dlamblin's post and Artilheiro's post as well).
What I cannot seem to find in my many days of research is the schema ...
1
vote
1answer
78 views
Design Issue: How to design the data model for SAAS based application?
Designing data model for STANDARD and USER SPECIFIC records for SAAS based model.
In my SAAS based application, I have users and their associated (One to One) roles. Tenants can create their own ...
0
votes
5answers
998 views
Data Modeling: vehicle's year, make, and model?
I'm trying to model vehicles at a basic level. Here's how I see the data:
A "year" (e.g. 2010, 2011) has 0 or more "make" (e.g. Nissan, Honda)
A "make" has 0 or more "model" (e.g. Nissan has Sentra, ...
0
votes
1answer
48 views
Data Modeling : Item With Dimensions (One-to-Many)
I need suggestions on how to properly model an item record along with all of its corresponding dimensions.
Consider the following:
| ITEM_ID | ITEM_DESCRIPTION | ITEM_PRICE | SIZE | LENGTH | COLOR
...
2
votes
1answer
202 views
What are some good, free data modeler programs available for Linux that work with SQLAlchemy?
I am looking for some good, free data modeler programs for Linux that are painless to install and work with SQLAlchemy. Any ideas?
2
votes
2answers
1k views
Tools to visualize a database and understand the datamodel quickly
I have several SQL Server 2005 databases ranging from 20 – 600 tables in an application and no documentation. I am looking for a database diagramming tool that is smart enough to pick tables that seem ...
0
votes
2answers
86 views
Rails need to make this data model better
I'm trying to create a data model for a rails app.
Basically I have a locations table that contains records for four different locations. I'm trying to create timeslots for each location for every ...
0
votes
2answers
71 views
Неlр tо dеsign dаtаbаsе tаblе struсturе
I'm writing application using relational database. I have entity of document that have to be persist in the database. The document is simply large table with many rows and columns:
But problem is ...
1
vote
4answers
512 views
Dynamic Typed Table/Model in Java EE?
Usually with Java EE when we create Model, we define the fields and types of fields through XML or annotation before compilation time. Is there a way to change those in runtime? Or better, is it ...
0
votes
1answer
57 views
Data model advice for Mongo collection that contains complex objects
we store apple app data in a database (http://www.apple.com/itunes/affiliates/resources/documentation/itunes-enterprise-partner-feed.html).
we want to optimize for one type of query: find all apps ...
0
votes
0answers
29 views
what is the assocation name in this ERM diagram [closed]
what is the name of name of assocation between property and measurment and Trait tables in this pic
Trait is a descriptive property like color; measurement is a numeric property, like height.
so ...
0
votes
2answers
510 views
How to keep ordering of records in a database table
i am creating a database table that is going to store menu links that will ultimately show up on a web page.
My issue is that i want to control the order of the menu items. I could have a field ...
0
votes
1answer
38 views
How to model linked accounts like this in MongoDb?
My application has both facebook and twitter users. Now users can merge two accounts together which means they can login with either facebook or twitter account.
Right now, I have a model like this. ...
1
vote
3answers
674 views
How to make use of Entity-Relationship diagrams to model mathematical expressions?
I am a newbie in Entity-Relationship diagrams (ERD) and have some difficulty in trying to come up with the diagram/model for the following problem - I don't even have a clue on where to start. Is this ...
0
votes
0answers
36 views
IBM Infosphere Data Architect or Data Modeler, possible to diff two logical- or physical models, or DDL:s?
We have one production SVN branch with our IBM DB2 physical and logical models, as well as their corresponding generated DDL scripts. This schema is in production. We then have another SVN branch ...
0
votes
0answers
95 views
How to design many to many complex relationships
I am designing a mysql database but I do not know exactly how to express some concepts. Basically, the key facts are:
Each license_owner may allow different roles;
Each corrispondence between role ...
0
votes
1answer
33 views
How to do advanced list modelling and matching in MongoDB
I'm building a university course search application and my data contains a pre-requisites field I need to match.
It looks like this: "Any English, Chemistry, Methods or Specialist Maths"
If I was ...
0
votes
1answer
77 views
data model for magazine store in rails application
I want to create a rails 3.2.7 application for online magazine store.
I design quick data model for this application but I'm not sure it is good or bad!?
I have Magazine table for all magazines, I ...
2
votes
3answers
485 views
News database design
I am making a news website but I want to let the user insert statuses from Facebook. The user can put the status anywhere in the news while writing it. I want to display the news as it's inserted.
...
1
vote
2answers
168 views
Database Mapping - Multiple Foreign Keys
I want to make sure this is the best way to handle a certain scenario.
Let's say I have three main tables I will keep them generic. They all have primary keys and they all are independent tables ...
0
votes
2answers
160 views
SQL Single Column Table
I have a model where a Shipment can have many Products through a product_shipments lookup table.
The Shipment model also has a relationship where a shipment can have one to many bill_of_lading ...
2
votes
2answers
161 views
store and query json in mysql table
I am trying to avoid anti-pattern in project where I must allow users to create, modify and delete table fields. So I am looking for storing JSON data in table. For example I have table products:
...
3
votes
2answers
90 views
Model database to represent constraints
I'm building a database (for a class) to model a parts ordering application. "Suppliers" provide parts (different suppliers may each supply one or more parts that fulfill the same role, and every part ...
1
vote
1answer
318 views
Difference between Row-Modelling and EAV
What is the main difference between Row Modelling and EAV (Entity-Atribute-Value)?
I think EAV is a subset of Row Modelling but I cant state the main differences.
If possible, please use references ...
1
vote
1answer
36 views
Implement deferrable validations
I'm faced with the task:
Input:
Data model, that presents huge entity via 20 - 30 relational tables (SQL DB).
There are a lot of constraints + reference data links.
Tasks:
Add a draft mode support, ...
1
vote
1answer
862 views
Draw Many to Many Relationship in ERD
Many to many relationships should have a solid line, strong relationship.
In the given diagram, ther right side sample is surely incorrect, the relationship
line show be solid. However, what is the ...
0
votes
1answer
264 views
Entity Relationship diagram from text tool
Is there any ER tool that can generate the model using textual input?
I am currently using dia which is an awesome tool, but i am looking for something which accepts text as input.
Thanks
1
vote
2answers
56 views
Query for status change first time
I have a table like below
CREATE TABLE Customers_History(Row_Id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
Cust_Name VARCHAR(255),
...
0
votes
0answers
45 views
Query to get rows whose status changed for first time
I have a table which stores list of Customer Details like below.I want the customers name whose status got changed for first time
CREATE TABLE Customers(Row_Id INT NOT NULL PRIMARY KEY ...
1
vote
1answer
120 views
Designing a user authenication (Roles & Rights) module
I am trying to model a User Authentication module for a MS SQL Server database that will be the back end to a Delphi UI Application. Basically, I want to have user accounts where the user belongs to ...
0
votes
1answer
63 views
Data Modeling for Ordering A “Package of Packages” filled with Items
Imagine an ecommerce platform that works as follows:
A Package, consists of a mixture of Items and other Packages.
An Order consists of a mixture of Items and Packages.
A user can select some ...
1
vote
2answers
133 views
How to manage key-value pairs storage when the value can be of several different types?
Let's say I've got n properties (pairs key-value) that are either dates, numbers or strings. Which data model is the most efficient to store them?
Here is a solution I thought about:
Each row of ...
0
votes
1answer
1k views
Top-down vs. Bottom-up database design: Real world examples
Ok, I can find hundreds of references on the internet of the difference between top-down database design vs bottom up database design approaches, however, I can't seeem to find any real world ...
0
votes
3answers
63 views
Designing a database without knowing the details of the data? [closed]
Are there cases where database designers are not allowed to know the details of the data? I am looking for real-world examples to learn from — please.
2
votes
3answers
214 views
What's the name of this data model pattern for representing real-world choice-permutations as a tree?
Say we are representing school course data. The relevant part of the example encompasses three real-world concepts: school, campus, and semester. A school can have many campuses, and there is a ...
1
vote
1answer
35 views
Realizing Three States By Storing Values in Single Column In DB Table
I Have List of Products Displayed in Web Page.
Each product is identified by unique product id in database.
Initially when the page loads its would be shown as Both tick and Cross under every ...
0
votes
2answers
154 views
Postgres FTS with array of composite types
Say I have the following psuedo-schema, where the 1-many relation is modeled using Postgres arrays :
CREATE TYPE quotes AS
(
text CHARACTER VARYING,
is_direct CHARACTER VARYING
);
CREATE TABLE ...
1
vote
2answers
111 views
cassandra highscore
If I want to have only the queries for:
1. Username, Xp, OtherUserData
2. User with the N-th highest Xp
How would I have to do the data structure and query.
For 1. I would have a structure similar ...
0
votes
1answer
113 views
Data Model for addresses with varying number of address lines
My question:
How would I implement a database design on the back-end and the front-end to accommodate a varying number of address lines such as AddressLine1, AddressLine2, AddressLine3, etc. into ...
3
votes
5answers
4k views
Data Model tools for DB2
I have created a Database in DB2 and tables with relationships. I would like to create a ER diagram based on my database design in DB2. MS SQL has a facility to create ER diagrams from DB schema, but ...
1
vote
5answers
168 views
Need database design advise
I have a Questions table which looks like that
as you see, there are 2 id rows that are nearly same: id, question_id. id - is autoincremented, unique id of each question, and question_id - is, ...
2
votes
2answers
133 views
Tournament management application - how to manage players and teams?
I'm writing an archery tournament management application. This application will be run on judge's laptop with no internet connection.
It is made to easily manage players, teams and their scores and ...
1
vote
0answers
36 views
To Share Data Directly or Make Copies
This is a very simple description of a complex system. The below stores and services have tons of relationships and millions of records of various types. Plus it is used by several applications.
I ...
2
votes
2answers
1k views
Database modeling for a weak entity
I have 2 tables in my database orders and orderHistory.
----------------- -----------------------
| orders | | orderHistory |
----------------- ...
2
votes
1answer
491 views
How I can efficiently check existence of a document in RavenDB
I have a domain entity Contacts, Contact is associated with lists via the MemberOf property (contains the list id in RavenDB)
public class Contact
{
public string Id { get; set; }
public ...
