The logical model and/or physical design of a database.

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1answer
48 views

Shared emails in a database [closed]

We lost our database administrator over a year ago - and even then she was promoted into the job internally and sort of learned on the job. Basically I say this to establish that strong data standards ...
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0answers
198 views

Database normalization tables

I am creating a database for a very basic website. I have created the tables and put what I thought might be the correct schema, however I am having doubts about it as well as a couple problems. All ...
8
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1answer
2k views

Database design for handling 1 billion rows and counting

We receive real-time GPS data at a rate of around 5000 pr. minute (from 4 TCP servers). Each server uses a single connection to insert the data, and buffers data in between inserts. Every 15 minutes ...
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0answers
26 views

Difference in the workload related to data-amount and search option

A couple of days ago I was asked why it is necessary to use the first normal form also for separation of names. We have a table which stores private customers (Name+Surname;Information) and business ...
2
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2answers
122 views

General structure advice for beginner

I am starting my first DB-Driven website project for a mock real estate agency and would like a bit of feedback on my general approach to how I will drive the site with the DB. Specifically I'm ...
3
votes
1answer
950 views

How to normalize my db schema for a quiz application?

I am putting together a quiz application. (I'm calling each quiz a "challenge") I have a "challenge" table and a "challenge_question" table which is pretty straightforward. challenge table: id ...
1
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1answer
929 views

Design for active/passive Master-Master mysql Setup

I have a dozen virtual machines running application + mysql instances (version 5.1 up to 5.5). Due to the bad I/O of the virtualization I want to buy a physical server for mysql and move all mysqldata ...
1
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1answer
184 views

How to design to avoid two-way reference between two tables [duplicate]

I am having a problem with foreign keys between two tables. I am trying to model a relationship between members of a club and their relatives. This is a straightforward many-to-one relationship, with ...
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1answer
85 views

How can I handle conditional fields?

I am in the process of designing a database for my company to assist in asset management. I'm not a database administrator, but I had some previous course experience with databases. Our assets are ...
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2answers
85 views

How to deal with circular foreign key

I have two tables: Games( name, current_step, #foreign key to Steps table #other fields... ) Steps( name, game_id, #foreign key to Games table #other fields... ) In other ...
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1answer
65 views

Which one is correct and optimized in sql?

Imagine that I have three entities (EntityA, EntityB, EntityC) that can have some images. So there are two ways: Make an image table for each entity. It means that EntityA has a image table named ...
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1answer
55 views

Decomposing into 2NF

I'm currently studying normalization. I know how to normalize the data for given unnormalized list. But I found this question in our past papers. I don't know how to answer to it. Q. Decompose ...
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1answer
103 views

UK Addresses in 3NF

I am in the process of creating a UK only database which holds information for various sets of people i.e. Staff, Clients etc. The tables for each of these sets of people have an Address, City and ...
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1answer
1k views

How much the decision to use ternary or binary relationship influences the accuracy of the model with regards to a given business model?

The question title is very long, so here's a little bit of context to (try to) make it clear. I asked a question regarding ternary relationship. The question was Ternary relationship: what's the ...
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1answer
6k views

Ternary relationship: what's the difference between having single table and having multiple tables?

Consider the following ternary relationship: Suppose that all entities have only two attributes (PK and Name). Here are the tables I derived (5 tables): Sector ------------------------- ...
0
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1answer
259 views

Conversion of simple ERD to Table: is the solution below any good?

Consider the following ERD: Suppose that all entities only have two attributes: a PK plus a name/number. I want to convert that ERD to tables. Is it needed 4 tables (1 for each relationship ...
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1answer
101 views

Database analysis

I have database which that store the sold products in Orders Table and another table called Transaction to set the time and the total price for the individual order ,my question is: How to combined ...
2
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0answers
122 views

Should I use SQL Azure to store product descriptions and links to images in Azure Blob

For an html/Css/JQuery public Azure website to be coded using Zurb Foundation html5 responsive framework, I'd like to use SQL Azure (web edition) to store product descriptions and links to images that ...
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1answer
5k views

MySQL Workbench EER Diagram and ENUM data type

I am creating EER model diagram using MySQL Workbench (version : 5.2.47) The version for MySQL, I am using is 5.5.35-0ubuntu0.13.10.2. I have created a schema with 'Default Collation' set to 'utf8 - ...
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2answers
207 views

JOIN on variable number of columns

I have the two tables courses AND something_about_courses: courses course_code course_session course_type something_about_courses course_code course_session some_description To ensure that I ...
0
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1answer
192 views

How to structure renting and sale as type of purchase?

I'm currently planning a database which involves two different types of Products that can be bought outright, or rented for a weekly or monthly amount. I'm just trying to figure out how to structure ...
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1answer
199 views

Is this design in 3NF? Why to choose another design not in 3NF

Having the following entities: Objects, Parts, Subparts and Items, and given the following design restrictions: A Part belongs to one and only one Object. A Subpart belongs to one and only one Part. ...
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1answer
61 views

ORM for Image model

I'm uncertain as to how a certain table should establish relationships, and I feel as if the solution I came up with is incorrect. The images table is used to store an absolute path on a server ...
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0answers
196 views

How to convert this relation to 2NF?

In my Entity Relationship Diagram, an entity type TEACHER had a relationship of TEACH with another entity type called CLASS. CLASS was a week entity type of TEACHER,so when mapping to a Relational ...
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4answers
143 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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0answers
2k views

Database design: Normalizing a “(many-to-many)-to-many” relationship

Short version I have to add a fixed number of additional properties to each pair in an existing many-to-many join. Skipping to the diagrams below, which of Options 1-4 is the best way, in terms of ...
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1answer
75 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 ...
2
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1answer
298 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
232 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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1answer
63 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 ...
2
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2answers
216 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, ...
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1answer
35 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
44 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 ...
2
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1answer
295 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
42 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
72 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 ...
0
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1answer
37 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 ...
2
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1answer
2k 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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3answers
17k views

MySQL vs. Microsoft Access [closed]

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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2answers
864 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
96 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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0answers
49 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, ...
0
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1answer
215 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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1answer
44 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 ...
2
votes
1answer
601 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
41 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 ...
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1answer
365 views

Database Design for NoSQL Fantasy Baseball League

I am trying to create a proper schema to place scraped data into, using a MongoDB database. Currently it looks like Team { id : id, name : String, teamLink : String, username : ...
0
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3answers
65 views

Should this be a foreign key? [closed]

I'm working on a school project and I need some help. I want to create three tables which should contain these fields: User UserID (AI, PK), UserEmail, UserPassword WorkGroupMember GroupID(PK, FK ...
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1answer
8k views

Database design for eCommerce website with multiple products having huge specifications index [duplicate]

I am designing a web site for online shopping and I have a question related to that. As you know that shopping website may have different product with different statistic/specification. What is the ...
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0answers
367 views

How to increase application performance with Centralised SQL Server [closed]

I’m trying to get my head around to make better way to increase the performance of my application System based on single SQL Server with 50 clients tablets pc(its connected to local wireless). my ...