Database design is the process of specifying the logical and/or physical parts of a database. The goal of database design is to make a representation of some "universe of discourse" - the types of facts, business rules and other requirements that the database is intended to model.

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Usage of foreign key when the referenced table data will not change

I have to design a table where user has 10 fields and 6 are dropdown. Some are single selections and some multiple. Dropdown data is supposed to change very rarely. For e.g., the user is presented ...
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1answer
683 views

Designing a database for a site that stores content from multiple services?

I'm building a site that implements David Allen's Getting Things Done that pulls in your email, Facebook newsfeed, tweets from those you follow on Twitter, and more services are planned. The problem ...
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4answers
63 views

Advanced design question related to compound primary keys

As a database design expert, I had a discussion with an academic person about database design and I need some arguments on why some design is bad or not normalized or bad practice. As we cannot ...
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27 views

How to design a database structure for different groups of contacts?

I've been looking around for a while how systems manage their contacts. Most I encounter is creating a people or party table including a type to define the type of people/party. These types are either ...
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1answer
34 views

Create one-to-many to two fields in different table

I have a database where I am trying to figure out how to join a table that contains an object called ModelType. The calibration table contains two fields (EffModel and BkgModel) that are based on a ...
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1answer
51 views

data warehouse design help

I'm struggling with the design phase for a data warehouse. It's not the traditional sales example you find on MSDN or all books etc. I've been tasked with creating an education data warehouse, that ...
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2answers
31 views

Relations between a imeid, sim chip, and account from a cellphone company?

I've never really had a cellphone (that I owned the account to...long story), but at work we have them, and we want to get a series of relations between accounts, devices (mifi's, tablets, ...
2
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2answers
303 views

multivalued weak key in ER database modeling

I was wondering since i didnt find out any clarification for this. I want to store movies that exist in different formats (dvd, bluray etc) and the price for each format differs from each other as ...
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1answer
60 views

Does this medical database look correct?

I'm pretty new to databases and I'm trying to create some schemas. I've been working away at this one for a while, but I can't help feeling that it doesn't look right. Essentially I have the ...
2
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1answer
49 views

Clustered composite key high fragmentation and fill factor

I've recently made a table to hold the language preferences of my users as follow: CREATE TABLE [dbo].[systemUserLangPreference]( [systemUserID] [int] NOT NULL, [langID] [int] NOT NULL, ...
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1answer
58 views

Which database (Graph, Riak, etc.) would most aptly solve the following problem?

I am working on a project and was wondering if a Graph database would best solve the following problem: (This is a simplified question) Say that you have a list of friends and you want to see when ...
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1answer
103 views

Best Approach to storing chat history?

I'm building a chat application (Yes, another one :P) and am really curious about the best way to store a chat's history(String username, String Message, Time, and possibly string channel depending on ...
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1answer
166 views

What is Transaction Path Analysis?

I came across the term Transaction Path Analysis which I am not familiar with. A Google search resulted in only a few results, most of which seem to assume everyone knows what it means. From these my ...
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27 views

Is it Ok to have one table with two relations?

I have an event table that has two kinds of participants. Each event will have many participants of each type. Is it good form to have a separate table for each participant type, each related to the ...
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1answer
60 views

Help with “Flexible” vs Fixed Tables

We are designing a database in SQL Server to handle sales commissions. A diagram of the current schema looks like this: There are only a couple of us on the project, and our boss dropped this ...
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1answer
71 views

Designing a reservation system schema

I am not sure if this has been asked before, however I am tasked with designing a new reservation system for my organization We have an older system which simply stored the booking in a table, and it ...
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1answer
16 views

Duplicate Data from two column

i have a table which has only two column one is pid(Photo ID) and another one is tid(Tag ID) +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | ...
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1answer
41 views

Is there any way MySQL can list relationship cardinality between two entities?

I am working on the project where I have to analyse the MySQL schema. As a part of schema information, I want to list down relationship cardinality between different relations. Does MySQL stores ...
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1answer
24 views

Table join inheritance

I create db with Person, Client, Employee, Manager, Developer. I'm interested what is the best way to put the data in tables. In which cases should programmer unite Client in table hierarchy with ...
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1answer
282 views

Learning to draw entity relational diagram

I am trying to learn entity relationship diagram, following question is the objective. Information consulting firm has number of offices with employees. The employees can move offices depend on the ...
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1answer
60 views

representation in ms-access

I have a database in microsoft access. I want to know how to look up a singular datum from a reference table giving a dynamic set of values. Here is a representation of what I mean: I have the ...
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1answer
76 views

What's better here - a single column or multicolumn primary key?

Let's assume you have a table groups and a table item. Each item belongs to exactly one group. It is an inherent part of that group. An item cannot exist outside of a group and it cannot be moved to ...
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0answers
17 views

Basic Design Question about one to many in a table

Sorry for the basic question but I am new to all of this! Say I have a table named Runs, and each table has Run: id (primary_key) data (String - path to a data file) status timestamp ... ...
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1answer
199 views

Designing Simple Schema for Disaggregation of Demand Forecast

I am doing a simple database design task as a training exercise where I have to come up with a basic schema design for the following case: I have a parent-child hierarchy of products (example, Raw ...
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1answer
47 views

Modeling a db that has products: What are the good practices/solutions? How to treat grammar variations in the words?

The problem is: A Company belongs to a sector. A Company produces products. A Sector contains products. A Product belongs to sectors. Three entities: Company, Sector and Product. And it's a ...
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6answers
15k views

How to export an ER diagram from an Oracle DB?

I am developing this application with an Oracle database. I haven't been documenting the data model, but now an auditor wants to have an entity relationship diagram of my database. There are many ...
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1answer
25 views

Is it possible (or good practice) to register data upon Deletion of a record? What would be a better solution?

The problem is the following. A company has one or more representatives (a person who speaks on behalf of the company). When a representative is deleted, it's desired to keep it in an list called ...
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1answer
35 views

postgresql bigserial or sequence using jpa

I'm a java developer working with jpa, before to define the indexes in my entities i would like to known which one is faster o better to use?.
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1answer
74 views

Relation between multiple hierarchical taxonomies linked to a single entity

I am working on an online test application which supports multiple choice questions. I have created schema for taxonomy (classification) system to be used with questions. taxonomy(id, name, slug, ...
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3answers
69 views

MySQL vs. Microsoft Access [on hold]

I'm trying to aggregate about 500-1000 MS Excel files that deal with various small business issues (inventory, purchase orders, etc) and I'm currently trying to decide what kind of RDMS I should use. ...
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0answers
35 views

Free JSON cloud database [closed]

Is there a free cloud database service that can be accesed using JSON format? My aim is to create a HTML5+CSS3+JS website that uses this database.
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2answers
26 views

MYSQL Indexes when looking up on alternating sets of columns

I have a table that looks like: CREATE TABLE `connections` ( `connection_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `service_id` smallint(5) unsigned DEFAULT NULL, `parent_id` bigint(20) ...
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1answer
460 views

Database partitioning - Horizontal and Vertical sharding - Difference between Normalization and Row Splitting?

I am trying to grasp the different concepts of Database Partitioning and this is what I understood of it: Horizontal Partitioning/Sharding: Splitting a table into different tables that will contain a ...
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2answers
59 views

Implementing voting system like reddit/StackExchange?

In creating an application that would require a voting system similar to that of StackExchange or reddit, I want to know how the database tables should optimally be structured. So far, I have ...
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1answer
35 views

Recipe Health risk Database ERD structure

I have these tables: First table(Recipe table), Recipe recipeid(PK,AI) recipename ingredients Second table(Ingredients table), Ingredients ingredientid(PK,AI) ...
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1answer
53 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
43 views

MySQL DB structure with Main category and several nested sub categories

I am looking to create a set of fields on my webpage identical to what eBay uses on their category selection page when you are selling something. For my purposes I am doing motorcycles, power sports, ...
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1answer
52 views

How to design database for DNS?

What tables will be there.Also as read percentage will be significantly larger than write, is indexing on columns advised? What other precautions are necessary? For now, I can just think of 1 table ...
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1answer
348 views

Efficient way to move rows across the tables?

This is somewhat long question as I would like to explain all details of the problem. System Description We have a queue of incoming messages from external system(s). Messages are immediately stored ...
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1answer
55 views

Functional dependencies and candidate key example

Hi there I'm still learning for my examination and I got this exercise: A table is given: F-Name, F-Nation, Team-Name, Team-Nation ...
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1answer
172 views

Time series data for ad platform

I am trying to figure out how to store time series data for an ad platform I am working on. Basically I want to know some strategies/solutions for storing billions of rows of data so that I can ...
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1answer
52 views

Does redundancy exists in this table?

I'm studying a DB course and I found this table: In this exercise, the objective is to determine whether the table has redundancy or not. According to the definition of redundancy Data ...
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0answers
20 views

Organizing a couple tables in postgresql

I have a data structure that is represented like this: { 'question_id': 1, 'is_required': False, 'question_text': [ { 'id': 1, ...
2
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1answer
75 views

Schema for a Soccer club

I am designing a database for a Soccer club. A soccer club has several teams. Those teams have several players and a coach. Right now I have three tables: Club Team (foreign key to club) Player ...
12
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5answers
1k views

Are there DBMS that allow a Foreign Key that References a View (and not only base tables)?

Inspired by a Django modeling question: Database Modeling with multiple many-to-many relations in Django. The db-design is something like: CREATE TABLE Book ( BookID INT NOT NULL , BookTitle ...
0
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1answer
29 views

Should I assimilate all address lines to a single line?

I'm new here, so I'll keep my question straight and short. I am building a webapp that lets users select some product, submit their details and place an order. Currently, my ORDER table contains only ...
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4answers
91 views

How to handle table design with variable columns

I have a table design scenario and as a non-DBA type, would like opinions on which is more scaleable. Say you are asked to record information on houses for a metro area, starting with a small ...
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1answer
85 views

facebook group alike database scheme

Here are my requirements: one user can have many tasks one group can have many task one group can have many users only invited user by a user can be added into a group Does this db design appear ...
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1answer
56 views

Database Normalization: A Case Of The NULLs [duplicate]

I'm trying to learn about proper database management and am having a hard time with designing a database that doesn't rely on NULLs. If you think I'm crazy for embarking on this, it is because of SQL ...
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0answers
26 views

Second opinion about elimination of possible redundant database column

We currently have a Widgets database table were we track the widgets the company produces. When a widget is produced the widget information is added to this table. This Widgets table contains a Status ...