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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Why does data get corrupted in “large” text files - Reasons to use database

I am just starting to learn about databases and using mysql. I read that databases are more reliable than having large ascii text files and that ascii text files are more prone to corruption as they ...
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1answer
21 views

design DB review and check constraint for postalcode help?

Hi. I created this database to just to sharpen my skill. I have one Question - when I create I make the FOREIGN KEY personID in Addresses table but I changed it to be AddressID in Persons table ...
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1answer
77 views

Should I place my Quartz Scheduler tables in a separate database?

I am designing a web application that uses Quartz Scheduler to scheduler jobs. I have Quartz configured to use a JDBCJobStore, so it automatically stores each created job in its tables. I am ...
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0answers
107 views

Can somebody check this normalisation workings i think i am missing a step or a dependency somewhere

given these two tables: and: I need to first list them as an un-normalised structure(s) then i need to identify the functional dependencies/primary keys. Once i have done this i must represent ...
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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) ...
3
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2answers
196 views

Is there a well-known name for this “poor man's ref. integrity” schema design pattern?

Is there a name for the following database schema design/pattern? My eventual goal is to find more literature about the subject. Today's cursory net search was too full of generic words to be able pin ...
5
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1answer
74 views

Hierarchical structure with limited number of records per user

I am planning schema for an affiliate network. For all hierarchical queries I am using Postgres tablefunc extension but here is another problem. Any user can refer only 3 other users at max. So for ...
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2answers
104 views

Can somebody help me normalise this database/check my workings

I am new to database design/normalisation and functional dependencies. I have started a new database class in school this week and we have been given a worksheet that requires the following: This is ...
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1answer
33 views

Combine or Separate Tables

I have a single table that holds the following data columns: id = Auto Increment provider = Twitter or Facebook (depends what they use to login with) uid = User ID name = Their full name (e.g. ...
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28 views

How to join the tables in mysql to get wall messages and comments with name of person ? Only user and his friends messages

I have four tables in my mysql database as shown in the image url provided. I want to select data from the tables without duplication. I want to show messages and comments on wall according to the ...
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1answer
5 views

Source control makes sure my code is never lost, how do I make sure my users/orders database is never lost?

Everyone is recommending the use of git, automated tests, continuous integration, automated deployment and so on, to reduce human error during all stages of web development. I have yet to come across ...
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1answer
58 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 ...
2
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1answer
76 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 ...
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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 ...
8
votes
4answers
300 views

eCommerce orders table. Save prices, or use an audit/history table?

Im designing my first eCommerce schema. I've been reading around the subject for a little while, and am a bit confused about the relationship between an order_line_item and a product A product can ...
2
votes
1answer
45 views

Data Modeling for different roles

This is my first post here, so I hope its clear enough. I want to make an application for people who sell, buy, rent and fix a certain product. I need to create a database that would keep the data of ...
3
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2answers
44 views

Calulating savings between two schemes

I've normalized a single table to reduce the number of nullable columns from 3 down to 0. The idea was to save a little drive space but I'm seeing a 45% decrease in space needed to store the same ...
0
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1answer
47 views

Table design for departments with duplicate department numbers

How should I define a database table for my company's departments where we have a set of duplicate department numbers used by an upper management tier. dept_id dept_name manager_id ...
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0answers
30 views

Using MySQL As A Graph Database, Can It Be Done Efficiently?

So I am currently working on a startup idea with a friend and we've come a long way, it's somewhat functional and I've tried to not let database design decisions slow the progress of the site. As of ...
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0answers
137 views

Normalizing data to 3NF

I need some help with normalization. Here is the data in 0NF : **HOSPITAL SERVICES (date_hospitalization , id_patient , id_doctor , name , surname , PIN, duration_of_hospitalization , ...
0
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1answer
55 views

How to model complex database role relationships

The purpose of my application is the creation, viewing and editing of articles. The problem I have is that users will have different roles for an article or group of articles. In addition, the role ...
3
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0answers
75 views

Storing and querying rolling data in PostgreSQL

I have a large quantity of weather model data being put into a PostgreSQL database. The machine has 8 cores and 16 GB of RAM. I'm running PostgreSQL 9.3 with PostGIS 2.1. Each table will have a ...
0
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1answer
329 views

MySQL count multiple columns and sum the total occurrence

I have the following table, say, MyDRAW ... DRAWNO PRIZENO FIRSTD SECONDD THIRDD FOURTHD M123/14 8458 8 4 5 8 M123/14 7214 7 2 1 4 M123/14 1640 1 6 4 0 ...
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1answer
142 views

Can Anyone please review my database after I did the Normalization ?.Any suggestion is appreciated

User: User_ID,user_name,E-mail Staff: User_ID,Fname,Lname,DOB Student: User_ID fname Lname DOB Lecture: User_ID Admin: User_ID Position ID : P_ID,ROLE_NAME, Staff_position ...
2
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2answers
68 views

Is it important to design the database the right way from the beginning?

I'm a beginner web developer and I use MySQL and sometimes MS SQL Server. However, I don't have that much information about databases, just basic information to be able to build some tables. Now, ...
0
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3answers
141 views

Db Design of a Room Booking System

I plan on building a web based room booking application for meeting rooms at a company. The requirements are not set in stone and are pretty much left to me, as long as these core ones are met: ...
2
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1answer
65 views

Database Design guidance required

I have scenario where there is Table T with columns PK,A, B, C,D TABLE t ( PK, A, B, C, D ) i have to insert data from different sources ie columns A,B,C,D are calculated separately.. and they same ...
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1answer
114 views

Concept, ER model, “employee tracking”

I have to achieve 3NF with following specifications: Database where I will determine priority skills for specific jobs and track the employees ability to complete them. Train employees. Example of ...
3
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2answers
47 views

Best design for a many:many relationship issue

We have three types of entity, each with their own table: table:A(a_id), table:B(b_id), table:C(c_id) Each of these entities can have any number of email addresses and linked Twitter accounts. ...
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1answer
69 views

Autoclose property resets to true after attaching db even if model is set to false

I am using SQL Server Express 2008 R2. The auto close property of a newly created database will be set to value same as model db. In my case I have set autoclose to false for model so that when I ...
0
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1answer
27 views

Help with designing a multi relational schema / domain model

I am in the process of developing a web application with asp.net MVC. I am using Entity Framework to make a connection to my database. I am having trouble with a specific concept in my program. I ...
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1answer
87 views

MS Access + SQL Server for 1160 users - Is it worth it? (Please Help!) [closed]

Our school in Delhi (India) wants to develop a professional and robust in-house database (SIS) that should handle vast amount of student information, including admissions, registration, re-enrollment, ...
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0answers
30 views

Keys of a relation

I got relation: R = { (ABCDEF) , (A B F -> C, B C -> F, F -> A, F -> B, D E -> E, E -> D)} keys of this relation are: {BCE}, {EF} But i dont get it... why? Why not only {EF}.. it got less ...
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2answers
55 views

A simple database and Query System? [closed]

I am new to databases and trying to solve one problem in which I have to build a simple database having few entries and then querying that database and then recording that answers from the database. I ...
0
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2answers
101 views

Decomposition of a relation to 2NF and 3NF

I am trying to solve this example, but for now I can't. Can somebody show me, step by step how to decompose this to 2NF and then to 3NF? R = {ABCDEF, ABC -> EF, B -> E, E -> D} key of this ...
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1answer
59 views

design database for electrical meter data?

Hi just wondering how to I have .csv "Time 'datetime' Voltage 'double'"file that record Voltage usage from electrical meter each every minutes and database to record the data just want to normalize ...
3
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2answers
121 views

Design database for real estate property management?

I have design this database diagram to real estate property management just I want to see if I get it right especially the relation between properties and finances because I made it one(property) to ...
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2answers
203 views

How to convert SQL Server database file to MongoDB? [closed]

I have .mdf / .sdf files created in SQL Server. I want to convert them to MongoDB. How can I do this?
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0answers
40 views

Reverse Engineer just a few tables in CA ERwin Data Modeler r9.5

I need to create a DB diagram for each functional area in the DB. Hence I need to reverse engineer only some of the tables. I started out by following this article. However I got stuck on the step ...
0
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1answer
35 views

String templating technique

I am working on a fitness app that is going to deliver notifications to the user. I intend using MySQL events to populate the necessary tables, and then using an Ajax timer or Websockets or whatnot to ...
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1answer
46 views

Best way to handle column that doesn't conform to one particular type

I have a Settings table: CREATE TABLE `Settings` ( `Id` int(11) NOT NULL AUTO_INCREMENT, `Code` varchar(100) NOT NULL, `Name` varchar(250) NOT NULL, `Description` text NOT NULL, `Default` ...
3
votes
1answer
68 views

Which items are table entities and which are fields?

I'm a mystery novelist with a series of three books that will end up at around 20 novels. I am having trouble getting the tables and fields sorted out. I want to be able to: create a list of all ...
1
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0answers
106 views

SQLite Design: Better to have many tables with few columns or few tables with many columns?

I am struggling to figure out the best design for a Sqlite database that will hold data about Facebook pages so that I can calculate benchmarks for how the average Facebook page performs. I have an ...
3
votes
2answers
73 views

How can I enforce ensure uniqueness of an association with a time dimension?

I have a database table AB which tracks the association of A and B over time: create table AB columns ( ARef ..., -- FK of A BRef ..., -- FK of B Since as Timestamp, Until as Timestamp, ...
0
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1answer
22 views

Store last elements in a dedicated table

i'm thinking about something. Consider a table "messages" which stores messages between member. This table can potentially billions messages. Looking for all message from a message would become a long ...
0
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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, ...
0
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1answer
168 views

Float datatype with 2 digits after decimal point

In SQL server float datatype does not display leading zeros after decimal point declare @num as float set @num=5.20 select @num will dispaly only 5.2 But i want it to display as 5.20 After a ...
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0answers
35 views

Creating remote access database online to allow entry, storage, and retrieval of biological monitoring data and photos

Perhaps this message belongs elsewhere, but this appeared to be the most relevant stack site to ask my question. If it is not, could you possibly direct me to a more appropriate venue? I belong to a ...
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1answer
63 views

Database Designing Issue

I have a database having Millions of records in three tables. Now i want to split these three tables in multiple tables to reduce redundancy and data duplication. A lot of records(Persons) have ...
0
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1answer
104 views

Benefits of using Staging Database while designing Data Warehouse [closed]

I am in process of designing a Data Warehouse Architecture. While exploring various options to Extract data from Production and putting into Data Warehouse, I came across many articles which mainly ...