0
votes
0answers
75 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 ...
3
votes
3answers
118 views

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 ...
0
votes
2answers
177 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 ...
1
vote
1answer
46 views

Database design implementing support for different languages [closed]

Today I was practicing database design, for example I was trying to build a database design where I would like to store my favorite shows. I have normlaised this database to the third form (at least I ...
4
votes
1answer
114 views

Probable circular dependency, but query still runs

I built this ER diagram in MySQL Workbench and it will run and generate the database. My concern is that the relationship between the employees, departments, positions, and employment_statuses is a ...
7
votes
4answers
281 views

how to explain indexes

This question is about teaching: When I learned databases, we talked about indexes being like the card catalog in the town library. We had at least an author index, a title index, then the Dewey ...
-1
votes
2answers
200 views

Relationship between professor and course [closed]

I'm designing a database where I have a Course table and and Professor table. The business rules are : 1) A professor can teach many courses. (This is obvious). However, I get stuck in the second ...
1
vote
0answers
48 views

Where should a default setting field be?

I am creating a database to track occurrences of incidents on buses based on an existing system. Currently the drivers can set a default bus number, which is used to pre-populate the bus number on the ...
0
votes
1answer
185 views

Database with insert data every 2 minutes

I have a site to develop into PHP and mysql where I take, with a cron, every two minutes 10 xml from a server parse each and insert data into my database. Well this data are simple string (maximum 10) ...
1
vote
1answer
97 views

Approach for a 2,000 table migration

What might be the best approach when converting or migrating a database containing over 2,000 tables? Where would you begin to tackle such an issue? Steps to take in the first weeks of designing? ...
0
votes
3answers
97 views

Column partially determining accepted values of another column, should be somehow normalized?

I have a table that describes a set of properties (yes it's metadata, in this case there's a valid reason to have it in the database); among other things I tell the type of the data that can be ...
1
vote
1answer
51 views

Adding users to a list and sort by category?

I'm using SQL-Server 2012 and I would like to know how to solve this program. So: I want to create a page that allows admins to manage a project, and part of it, would be to add members/employees to ...
2
votes
1answer
172 views

Deriving formulas for input/output

I'm currently enrolled in a DBS class and am having problem with an assignment. I've searched around and have been unable to understand what it is I'm meant to be doing with this derivation formula. ...
0
votes
1answer
528 views

Keep total transaction in invoice application

I want to make an application called as Invoice Application with MySQL database. Now I have designed this database. Now I want to know is this database good for Invoice Application. I will use MySQL ...
1
vote
1answer
1k views

Planning simple CMS: How much relation?

I'm currently in the process of designing the database for a rather minimalistic Content Management System I'm working on alone. It should allow scalability while remaining speed, especially on boxes ...
0
votes
1answer
135 views

Database column vs row size

I have Column A and Column B in a single table. I need to add 1,000,000 records to this table. I have 2 options: Keep 2 columns and add 1,000,000 records Add more columns and flatten out the ...
3
votes
5answers
1k views

Does 'Cities' deserve a separate table?

I have the following Customers table: customer_id - int company_name - nvarchar street - nvarchar city - nvarchar comments - nvarchar The app will only be used in part of one small country ...
3
votes
1answer
845 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 ...
4
votes
2answers
995 views

Ready-to-Use Database models example

Where can I find ready-to-use database models ? I don't need a database with data in it, but only schemas (UML diagrams). Perhaps something like the data models at this link, but much more complex ...
0
votes
3answers
442 views

SQL Server : primary keys advice to my whitepaper needed

I've tired to explain to every new junior developer in our r&d team why he should use Primary Keys and how to do that. So I decided to write small whitepaper, which every new developer should ...
16
votes
1answer
594 views

What is the reasoning behind the CAP theorem?

http://en.wikipedia.org/wiki/CAP_theorem http://www.cs.berkeley.edu/~brewer/cs262b-2004/PODC-keynote.pdf I think it is not very straightforward why only two of Consistency Availability Partition ...