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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79 views

Is there better way to design SQL tables

I need to design a quick application for small warehouse. I just want to check if there is a better design approach. I am using polymorphic associations for comments tables. Business Rules If ...
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2answers
48 views

Keywords - column or separate table

I am building a website on MySQL with php, and I have 400+ products in a table. I have three columns with comma separated values, each has 1-3 values separated by commas in each row. I was wondering ...
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1answer
92 views

Storing a music playlist, best approach?

I am working on a web project that creates playlists online based on youtube links. My question is how do I store a playlist on MYSQL. What I was thinking about doing was having a table with ...
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1answer
34 views

Lookup tables and performance

I am using 6 lookup tables in my mysql database. There will be frequent insert,update and delete queries in the db. Will that badly affect the performance. Do I need to save the data as it is without ...
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1answer
203 views

Is this many to many relationship correct? [duplicate]

I'm reading this tutorial, and I have question about it. Look at this picture: 'Reading' the logical Relationship I read that a Project must have one or more Employee. But the physical ...
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1answer
121 views

Should I split these fields or leave as one?

I want to create a database listing characters in each book of the A Song of Ice and Fire series, listing the name of the character and the page in which they appear. I could just use three fields ...
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28 views

Preventing unique key constraint violation when pre-existing row has 'expired' [duplicate]

I have the following table schema; CREATE TABLE LOCKS ( lock_uid INTEGER NOT NULL, file_uid VARCHAR2(32 char) NOT NULL UNIQUE, owner VARCHAR2(255 char) NOT NULL, expires DATE NOT ...
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1answer
67 views

How to represent a many to many relationship with Crow Feet diagram

I'm designing a database and I want to represent the relationship between users and groups: A user can be on zero or more groups. A group can have one or more users. Using Microsoft Visio 2013 I've ...
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2answers
54 views

I don't know how to read many to many relationships

I'm reading this tutorial, and I have question about it. Look at this picture: Looking at Physical Many-to-Many Implementation I read the relationship this way: 'A user can be in zero or more ...
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1answer
114 views

Why do we not store names in a separate table?

Practically, I would never store names for customers in a separate table. But why not? It's a one to many relationship (a person can have one name but that name can be used by multiple people). ...
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1answer
48 views

Schema for dynamic number of attributes

I am implementing an application where users can save alerts for different services. Each service can have multiple types of alerts and each alert has X number of attributes to form a predicate. So ...
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1answer
197 views

HStore vs. multiple tables with inheritance - do I have a good use case for HStore?

My broader question here has to do with when it is appropriate to use HStore vs. multiple tables vs. one table for storing document-like objects. Now, for my localized example: I’m designing a ...
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1answer
48 views

Peer review database design for various reports

I'm currently trying to redesign a poorly thought out database for a peer review system that we use internally at my workplace. Employees can log on and submit a review about another employee who ...
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11 views

Removing a large amount of data from a workbench model

In MySQL Workbench you have the ability to add data (inserts) to tables you are designing. Currently I have a model with some tables, and I have added a lot of test-data to one of the tables. This ...
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1answer
264 views

How do I connect my MS Access database to the LAN? [duplicate]

I wrote a database program in MS Access a couple of years ago, and it is used to keep track of some personal stuffs. I now want to expand this personal project and allow several computers to have ...
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24 views

ER Studio Data Architect - Deleted relationship in sub model - need to sync up in main model

I have Main Model where I have few entities and relationships. I had pulled out few entities from the Main model into a submodel and was working on the sub model. whereby I had to delete few ...
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1answer
150 views

desing the database for survey app with various types of answers

I have to create a survey app for which answers should be stored in the database. I created an html form containing some questions (about 30) with various types of answers (check boxes, radio buttons, ...
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1answer
39 views

Create menu from multiple meals relationship

I have the following relations: Meals(meal_id, name, cuisine, ingredient) Users(user_id, name, username, password, email) Chefs(chef_id, name, username, password, email) I want to create the ...
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1answer
73 views

Confusion normalizing data to 3NF and transitive dependencies

I am currently in a Database class and have some confusion with normalizing to 3NF. I have one specific issue that was not addressed in class but appears in the book problems. For example I have R ...
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1answer
81 views

Relational Model Design - Entity with one attribute

I am trying to desing a database relational model for an assignment. At first, I design the ER diagram and next the relational model with tables(Schemas). So here's my question : Is it possible for an ...
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1answer
284 views

Database design for mobile app

At first I would like to say hello to all of you, since it is my first post here on DB Administrators. I am writing an app which store drinks and their data. At the beginning it was storing all in ...
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0answers
84 views

How would I model the Twitter lists functionality?

I'm working on an application which would mimic the Twitter Lists functionality in which someone can follow someone else. Each user can also create objects which can be followed by users. The Twitter ...
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1answer
173 views

Multiple product attribute inventory database design

i have a database to build based on inventory for my shop. this is the current data that i have put into tables this is the package: this is the product attribute this is the table to produce ...
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1answer
151 views

Airport Database Design guidance required

I am trying to make a generic database for airport management and DBMS would be oracle 11g xe. Since, i am amateur and still learning so i have tried to kept the problem statement simple with limited ...
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16 views

Database design and Technology [closed]

Can someone point me in the right direction for this scenario as I am designing a website: Its a portal where people can save customer details in the cloud. Now i want my main website to allow them ...
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19 views

loading k:v pairs from DB into JS Object

I'm creating a single player web RPG. I'm debating the following method of storing/retrieving quest items per player id: In userstats table, have a quest_items column of type mediumtext, where I ...
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1answer
78 views

Rules for Decomposition to 2 NF

I am struggling with the concept of 2NF form. Lets say I have a set of functional dependencies for R1(A,B,C,D,E,H,M,K) Where : B -> M,C AB -> D DH -> E H -> K A -> H Whenever I ...
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196 views

How to generate data for News Feed efficiently like facebook , googleplus , twitter e.t.c?

I have created table as post ( post_id int(15) auto_increment primary key , user_id int(11) , post_text varchar(2000) , post_type int(1), ...
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1answer
74 views

What is the advantages of using auto_increment in database as primary key over set of attributes?

I have table as CREATE TABLE circle ( circle_id int(11) auto_increment primary key not null, user_id int (11) not null, title varchar(255) collate utf8_general_ci not null ); CREATE ...
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1answer
79 views

What is the strategy of query evaluation in DBMS when Limit is used in query?

I have following tables in database post(post_id , user_id , post_text , parsed_text) ; Comment(comment_id , post_id , user_id , comment_text) ; friend(id , user_id , friend_id ) ; group (id , ...
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35 views

Relationship cardinality different in subclasses

I need to design a concert management database for as a class project. So far I defined an "Event" entity, subclassed in "Festival" and "Concert". Festival is intended to last one night or more and ...
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1answer
744 views

Airline reservation system [closed]

I'm making a simple airline reservation system. But I'm not sure about the design decisions I made. Concretely, I'm trying to implement following constraints: each Aircraft can have one or more ...
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1answer
175 views

What is the correct way to ensure unique entries in a temporal database design?

I'm having trouble with the design of a temporal database. I need to know how to make sure I have only one active record for any given timeframe for a store. I have read this answer, but I'm afraid I ...
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2answers
71 views

Is my ERD valid for airports,cities and airlines database?

My objective is to make a database of airports, cities and the airlines which provide coverage to them. I asked the question before on stackoverflow and the person told me to break up the ...
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1answer
105 views

database design for dynamic menu bar [closed]

I am trying to create a menu bar which will load dynamically on user log in, based on the user roles. Say if the user is an admin he can see all the items listed under the header and if a user is a ...
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0answers
55 views

Book about database design patterns [closed]

This question was asked before, but I have different needs. I know how to: query the database with SQL create triggers and stored procedures create databases (with 1:N, N:M and 1:1 relations) ...
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4answers
144 views

Mass data upload from Excel - technology

I am a Developer seeking help in terms of DB technology for a specific requirement. I have done some research but can not conclude with list. Requirement: There will be a web application which will ...
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2answers
557 views

Alternative to EAV for dynamic fields in a star schema data warehouse

I need to support dynamic fields and values in a big datawarehouse for storing API requests log, my user case is that I need to store all API requests query string and able to perform query against ...
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29 views

Enterprise system database strategy [duplicate]

Here is my current database design: Separated databases based on area of domain (Sales, HR, Accounting, Core such as login and menus, etc). Each database has a single service login, each with ...
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234 views

How to design Saas application's database architecture in mysql

I have to develop a Saas application using Yii php framework and mysql. For developing this we have decided to make separate database for each customer. For this I need a effective basic database ...
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32 views

Normalization to BCNF help needed

I have a table with 5 columns as A, B, C, D, and E. The functional dependencies are: AB -> C,D,E BCD -> A BCE -> A,D BD -> E I think AB is the candidate key. I can't find any other candidates. ...
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1answer
45 views

Is it OK to duplicate parent field in child table for performance?

I have a very complicated query which involve more than 10 tables. Some parent tables are loaded only to search on one field. I wonder if I can copy this field in the child table (this data is never ...
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1answer
41 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
97 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 ...
6
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1answer
622 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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22 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
94 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 ...
2
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1answer
335 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 ...
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36 views

more queries vs storing results in database

Environment: Embedded (smartphones) Data Structures: Object Table A: id, field1, field2... Object Table B: id, field1, field2... Object Table C: id, field1, ... , Object A, Object B ... many ...
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1answer
84 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 ...