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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Relational Database design best practice

I am a student and I am trying to design a simple database, so if the ideas seem bad please let me know how to improve. I have three tables in my mind, one for Professors and one for Students. Both ...
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Understanding how relationship sides works

So, I have this relations on my tables (see image) and I need to understand some things. I'll enumerate what I understand and what I need from yours is to say if I'm right or not and in case I'm not ...
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29 views

eCommerce product table design - MySQL

I am designing database for an web application, I have designed the product and specification details database as follows, create table pr_size ( size_id int not null auto_increment, ...
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compare file-based systems and a relational database

I don't know the exact difference of both can you please compare file-based systems and a relational database?
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73 views

Duplicate Relationships in Rails/MySQL Healthcare Application

Overview of the Application I am building a Ruby on Rails application to organize medications, using MySQL. The goal of this application is to provide dosage specific treatment recommendations, and ...
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Redesign tables, multiple foreign key and related table to same table

Hello I have this database: Table Teams is used in each one table. Match table contains teamA and teamB and round contains team that win the SET and team that start the set. But I dont know how I ...
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45 views

How to model ski rental equipment

I've spent a good amount at time at looking at related posts regarding products for rent but still have a few unanswered questions. If we consider the just the requirements at hand which is how to ...
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4answers
213 views

Database/Storage engine suggestion for a project involving heavy inserts?

I am looking into a project which involves large number of inserts daily.I will have a list of user's (for example a user set of 500k ) , for which I need to monitor daily certain activities ...
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1answer
21 views

Table income and expense is better to have it together or apart

I am developing a small system where I have to record incomes and expenses of the company, and even I can not determine if the income and expense table should be in one table or in separate tables. ...
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1answer
19 views

How to create trigger with NOT FOR REPLICATION

I tried adding "NOT FOR REPLICATION " in many parts in the below code but ended up in the below code. I searched a lot for an example where I can see how its done with a trigger. Can any one show me ...
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2answers
45 views

One table with a flag or two tables

I have a problem with the design of a database: In my Android application i need to store the upload (the status, so if the file is in upload it will report the % of the upload) of a file and a list ...
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1answer
27 views

Need DDL for an Oracle Table that would be 1 row = 1 8K Block

For performance testing in our performance environment we want a means to turn over SGA the way production does. Our performance environment is a fraction of production and production's very nature ...
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1answer
49 views

Best relationship database design to manage types for different entities

Suppose we have to manage phone types for: Clients, Employees and Suppliers. Each of these can have multiple phone numbers, so for better management I would like to add phone type. Each entity can ...
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1answer
37 views

Difference between Relational database and time series database?

I have a bit stupid question maybe. I recently came across a term "time-series database". I would like to ask what is time series database and is it same as relational database? Thanks,
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2answers
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Do I need foreign keys in ORMs?

Object Relational Mapping (take ActiveRecord and Rails, for example) allows a programmer to define relations between models, and callbacks on delete. So my question is: do I still need to define ...
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1answer
59 views

Different type of column

Maybe the title is misleading but I'll try to explain what I'm trying to do. I'm building an e-commerce site. I have my products and my order. I want add constrains on how the order will be deliver ...
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0answers
74 views

How do you think in NoSQL? [closed]

I'm from the pre-nosql era and am rather comfortable with SQL. However, I cringe whenever someone suggests using a NoSQL database for the "upcoming" project. There are some major problems that I'm ...
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24 views

Database Design to administer customer-specific Network Information [closed]

My intern-job is to implement a small Database Front-End as an Intranet-site. The Front-End will directly access their primary database containing all the customers informations. The company I work ...
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1answer
58 views

What is a good/healthy mysql query execution time?

What is a good/healthy mysql query execution time? To my calculations: The site gets 1000 unique visitors per hr 10 page view for each unique visitor 5 minutes for each unique visitor ...
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1answer
46 views

Reviewing relational database tables

I am building a database, but I am a little bit confused with my table relationships. I wish someone could help review my table relationships below for me and tell me where I am going wrong. I have ...
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2answers
52 views

Help required to design a database [closed]

Firstly I would like to apologies if this is not the correct place to ask this question but I know how good community spirit is around here from my time in Stack Overflow. I am very new to the world ...
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23 views

Dealing with Multiple User Roles

I'm working on a project based on a CMS, where there is a built-in roles table. However, the CMS allows a user to have one role only using role_id And these are the requirements that struggling me: ...
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3answers
74 views

Many one-to-many relationships between two tables

In the process of creating a small database for a therapeutic boarding school with Access 2013, I have a problem when designing the relational database model. Two times at least, I ran into a ...
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21 views

Justfity the relation of Multi Value Dependecy(MVD)

let say i have this database table: This is how i justify the relation has the Multi Value Dependency (MVD) { Book } { Author } | { Edition, Year } as below. "Because the author attached to the ...
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Trying to get BCNF out of this relation

The table is: Employee ( EID, Ename, PID, ProjectName, MID, ManagerName ) For the functional dependencies I got: EID==>(Ename) PID==>(ProjectName) ...
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1answer
57 views

Row Level security or Multiple Tables

Im looking for documentation on best practices for the following scenario. A hosted application contains some "global" data and some "Per-tenant" data. A "Tenant" should have no access to another ...
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20 views

Minimal db structure for multiple parents and multiple children nesting

I stuck trying to do regular category nesting with noSQL db like parent -> child -> child but in one table. DB engine is parse.com so i got pointer and relation as db relation options. what ...
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1answer
22 views

Save different account types in a database

I have the following issue. In one application (imagine a messaging/e-mail app on your smartphone), the user enters its accounts and gets information from the server displayed. I need to store the ...
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1answer
39 views

Optimal table design for a medical center rental service and recurrent shifts

I'm trying to figure out the optimal design for the following situation I'm being presented. I'm developing a medical web application with MySQL as db engine. A medical center has 14-16 offices/rooms ...
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3answers
67 views

Entity Relationship Model - double one to many

ERD A customer submits one or many leads. A lead belongs to one customer. A lead is a request or an inquiry. A lead belongs to one manufacturer. A manufacturer has one or many leads. Tables ...
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Optimize finding the next batch of data from A to be crunched and inserted into B

I'm using PostgreSQL to store data produced by a large distributed computation. There are several stages to this computation; the idiom we've settled on is that there's a table containing the results ...
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6answers
448 views

Database Normalization - Can one field point to another?

This may sound like a dumb question, but I am a software developer new to database design... So the concept makes sense to me, but maybe this doesn't carry-- Is it possible for a field in a record ...
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2answers
41 views

Designing a Course Equivalency Database

I am trying to create a database to store information regarding equivalent courses transferring from one school to another. I am struggling to conceptualize the relationship in a way that can ...
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1answer
38 views

Problem creating database using default mdf and ldf path

I'm trying to create a database using the default paths on several SQL Servers at once. To achieve this I'm trying to use a script that should create the database on each server, however I've run into ...
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1answer
58 views

Creating and designing Air Trafic Control System [closed]

I'm having a class about Database management system, and the prof. gave us a project regarding Air traffic controller system, exact question is "Design and create a system which can manage ...
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1answer
57 views

Can I get some comments on my database design? [closed]

I have designed a database for my institute. Here I have attached my design for better understanding. I am expecting your reviews who are professional for the database design.
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45 views

Normalization of Time Series Data

I have a table containing various a/b test experiment performance on a daily basis. The table structure looks something like this: date | experiment | user_count | user_attr | sales ...
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53 views

Best way to store immutable/read-only copies of data for logging?

I'm storing data about tasks like so TASK (id, name, employee_id, machine_id, ...) For logging purposes I would like to store any information about that TASK once it was made. Since the reference ...
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1answer
52 views

Documenting a collection of databases and their relationships with each other

As part of a project I'm currently involved with we need to identify where various data points are held within existing systems, with a view to integrating them into our central integration engine. ...
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1answer
110 views

Horizontal schema vs Vertical schema

I am but a modest SQL DBA. I would like to request your advice on the design of the central part of our new proposed database. Brent Ozar had something to say about this: Building A SQL table ...
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1answer
48 views

Should I use a surrogate key in a mapping table?

I am deploying a mapping table which connects Items to ItemGroups Though an Item will only ever be in a single ItemGroup please accept a priori it is not appropriate in my use case to append a column ...
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1answer
46 views

Database design Problem for the web-app

Hello I am in a problem of designing a web-app database schema. Suppose I have 10 shops and every shop gives deals on every different day Sunday, Monday and so on and for limited time period like ...
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48 views

“Wide” vs “Long” Database Structure - Is there a logic when to use which? [duplicate]

I'm currently setting up a database to house records for an application I'm writing and am trying to come up with the most efficient DB structure to use... Of course I know that there are as many ...
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1answer
32 views

SQL - Query on table creation, referential integrity

Please let us know what does the below definition means on table creation. CREATE TABLE A(w INT PRIMARY KEY); CREATE TABLE B(x INT PRIMARY KEY REFERENCES A(w) ON SET NULL) As per my understanding, ...
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2answers
57 views

Postgresql: datatype for email address

What would be the right datatype to store email addresses in PostgreSQL? I can use varchar (or even text), but I wonder if there is a more specific data type for emails.
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1answer
50 views

Review database schema / thought process

Please review my thoughts below. It is written in an authoritative style because it is the most succinct, not because I am competent. Please poke as many holes as possible. I am trying to create a ...
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50 views

“Replicate” Table structures with sp_addscriptexec [closed]

In our customers environment is a massive central server (running SQL Server Enterprise 2008R2) and some distributed PCs (running SQL Server Standard 2008R2). The central server has a replication for ...
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2answers
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Table design for multi-type data

The information model I am modelling from includes an "any type". For example a customer can have zero or more 'entries' each of which can have a number of values. Each value could be a either date, ...
2
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0answers
38 views

Constrain referenced rows to two different tables to belong to the same row in another table

Apologies for the potentially confusing question title. I struggled to make it generic! I am designing a wildlife recording database. An observer goes to a site and records the occurences of species ...
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2answers
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Is there a reason to store currency amounts as fractions instead of decimals?

I've been reviewing GnuCash's DB design and I found that they are storing amounts as two 64-bit integers, the numerator and denominator of a fraction. Is there some advantage from a DB perspective to ...