0
votes
1answer
33 views

ERD Design for Employee Leave

I found the following ERD design: Which trying to capture as much information about employee leave (i.e sick, travel, etc). What am trying to understand is what does the columns: Table : ...
1
vote
1answer
63 views

Friendship and Messages in a MySQL table relational schema problem (concerning big data manipulation)

Before you start suggesting this question for duplicate read it, I have searched and i haven't found any proper solution. So, i'm building a social networking site (I know that you are laughing ...
1
vote
2answers
34 views

DB for storing simple time-stamped values

I don't have that much experience in databases but I need to accomplish this as best as I can. It is rather specific. Database will contain only data structured like this: dataID-timestamp-value ...
0
votes
1answer
70 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 ...
3
votes
1answer
109 views

Optimum design / structure for product data database?

What would be the optimum design/structure for product data database, where each product have many variations and many attributes? Attribute sets vary between products, and some attributes have values ...
0
votes
1answer
64 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 ...
0
votes
0answers
33 views

Designing a multi-language searchable translation database

Good morning, I am currently building an application where I have different sets of terms(yes could be sentences) or words represented in different languages. Example: english | french | german | ...
0
votes
1answer
325 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, ...
0
votes
0answers
91 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 ...
0
votes
1answer
70 views

How to check how the table structure effects the performance of my query

I want to check how the table structure of a certain table effects the performance of a delete query. This is not a generalised question, I have a table, with currently 2.2 million records ...
1
vote
1answer
105 views

Product quantity bound to colors and sizes table structures

I've been thinking about how I'll be able to create products with sizes and colors which will match the max quantity of a product (or their total will be the max.quantity ). Let's say I got a product ...
-1
votes
1answer
43 views

One or two tables (for two things: cancellations and moves)?

A lesson may be canceled, moved to an other time, and possibly switched to an other teacher. In other words, we have lessonid INT UNSIGNED canceled BIT(1) time TIME teacherid INT UNSIGNED Should ...
1
vote
0answers
107 views

Are duplicates ever acceptable in a database

A warehouse system I am working on allows inwards consignments [type = 0] and outwards consignments [type = 1]. The user selects multiple products for each consignment and then multiple warehouse ...
2
votes
1answer
56 views

How to handle “or” possibilities in MongoDB

I'm new to MongoDB and by no means an expert in DB design in general. This feels like a really basic question that's probably been answered a million times, but I'm having a surprisingly hard time ...
3
votes
1answer
1k views

Schema design: Use of association (aka: bridge/junction) table vs foreign key constraint with composite index containing a non-key field

This is an inventory database for IT assets. The models used are trimmed in order to focus on the problem at hand. Using SQL Server 2008. Thanks for taking the time to read and for any input you can ...
0
votes
1answer
64 views

Several variants of a string in tables

I need: a table containing keyword phrases; a table containing URLs; a table (or maybe a view) with keyword-URL pairs (referring to IDs of the two previous tables); tables holding keywords/URLs for ...
4
votes
1answer
96 views

How do you manage a list for particular object. for eg. user comments on specific object(user post etc.)

I am new to database and web application development. I want to know how to store a list for a particular object in a database. For example, user comments for a particular post(object), or the ...
3
votes
1answer
1k views

Under what conditions are polymorphic associations used? What are the alternatives?

As I understand it, polymorphic relationships among tables in a database allow one table to have one foreign key that references many tables. I have found that tags are a common application of this ...
2
votes
1answer
133 views

One table or several tables?

I have several types of writings: articles, projects, reviews, etc. I have a table containing paragraphs (fields id (INT) and partext (TEXT)). Each writing consists of several (ordered) paragraphs. ...
8
votes
3answers
7k views

Inventory database structure when inventory items have varying attributes

I'm building an inventory database to store enterprise hardware information. The devices the database keeps track of range from workstations, laptops, switches, routers, mobile phones, etc. I'm using ...