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.

learn more… | top users | synonyms (2)

0
votes
1answer
298 views

Converted ERD into Dependency Diagram 1NF, 3NF

Thats the ERD. I'm studying for an upcoming test and having trouble getting my head around converting thes ERDs into dependency diagrams. This is from a previous exam that the Lecturer told us to ...
0
votes
0answers
24 views

Optimal layout strategies for Time-Series using Columnar storage

In the context of time-series and specifically columnar storage systems. Question: What are the processes or heuristics that are used to determine how best the columns of contiguous values be grouped ...
1
vote
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 ...
1
vote
3answers
272 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.
0
votes
1answer
64 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 ...
2
votes
0answers
98 views

Should I use SQL Azure to store product descriptions and links to images in Azure Blob

For an html/Css/JQuery public Azure website to be coded using Zurb Foundation html5 responsive framework, I'd like to use SQL Azure (web edition) to store product descriptions and links to images that ...
3
votes
4answers
221 views

Best practice for a Table with private columns

I have a table with user data, where most of the columns can be public or private (so it will be shown or not on the app) and every user can decide which fields to hide. So far I had a couple of ...
2
votes
1answer
91 views

How do I add versioning to this CMS I'm designing?

As you can see, my CMS consists of several widgets (for example an Articles widget), of which you can create several instances, which I call blocks, and those blocks are linked to pages and the ...
1
vote
2answers
291 views

Optimizing large MySQL SELECT WHERE IN clauses

How can the following SELECT WHERE IN case be optimized? I have a table with over 100 million rows with only 3 columns. The primary key (col1) is a 127 varchar. I am performing a SELECT col1 WHERE ...
1
vote
2answers
99 views

Should a ledger DB store a separate line for each side of a transaction?

I'm working on a database that needs to do manage transfers between several accounts. We are considering using a simple ledger system for this (like what you find in Quicken). I have two concerns ...
7
votes
2answers
124 views

Should I add transitive foreign keys?

Simple example: there is a table of customers. create table Customers ( id integer, constraint CustomersPK primary key (id) ) All the other data in the database should link to a Customer, so ...
6
votes
3answers
1k views

Foreign keys - link using surrogate or natural key?

Is there a best practice for whether a foreign key between tables should link to a natural key or a surrogate key? The only discussion I've really found (unless my google-fu is lacking) is Jack ...
0
votes
1answer
41 views

modelling warehouse picking

What's the best way to approach modelling a warehouse picking system? To be precise, customers place orders which are processed by warehouse staff. A simple products and orders database isn't an ...
0
votes
1answer
25 views

Establishing referential integrity in a generic table?

Current Schema: - DropDown: DropDownID PK, Name nvarchar(25) - DropDownOption: DropDownOptionID PK, DropDownID FK, Name nvarchar(25), Description nvarchar(155) ...
2
votes
0answers
57 views

Which is the better schema design for a voting system?

Imagine a q/a site or forum similar to stackoverflow. I'm trying to determine which of these two methods would be the better design for a voting system: (note: I would also like to keep record of all ...
1
vote
2answers
63 views

how to design a database's table to store mysql spatial data in a parent child relation?

I want to store locations and polygon data in a parent-child relationship. I am using spatial data in MySQL and Google maps for polygon. Examples: 1. World 1.1 US 1.2 China 1.3 Japan 1.4 South ...
0
votes
0answers
22 views

Conditional value lists in MySQL

apologies in advance if the language I use here is insufficiently specific. Please let me know if there's anything that I can clarify. Does MySQL provide a means of creating conditional value lists a ...
1
vote
0answers
32 views

Identifying functional dependencies

I'm having trouble understanding the logic in use for identifying functional dependancies. Looking at the sample relation below, I understand fd1 - fd3. But when I look at fd4 and fd5, its logic ...
1
vote
2answers
53 views

Why WordPress use a column prefix? [closed]

I'm trying to learn some basic database design through open source projects. And look into the WordPress database schema, the posts table for example, you'll find something like this post_author ...
0
votes
2answers
46 views

What's the use of assigning foreign keys on MySQL [duplicate]

Aside from indexing the value of the foreign key, what is/are the advantage of assigning foreign keys to databases? I've seen a lot of databases that does not assign foreign keys, but is relational by ...
1
vote
1answer
45 views

Should I add new column or new table

I have an existing table called exampletable1, now i have been given a new list of data called "medicines" it only have: male,female as its value. I'm having a problem whether to add another varchar ...
0
votes
0answers
29 views

Same column relational Id to multiple tables

Is it appropriate to use a column as a relational id to multiple tables? For example: referenceId - int relational id to various tables tableReference - String defining the table This way I can ...
2
votes
2answers
417 views

Is there any way to do a SELECT query without any optimization in SQL Server?

I am trying to test the speed of SQL server queries. However, once I do the query once, it becomes a lot faster. The database is live so I can not make any changes to it, only to the SELECT query ...
0
votes
2answers
89 views

Composite Primary Key column order

How would you do the ordering of the PK columns in this case (Oracle 11gR2 Standard Edition): I have a database where I offer the same application to many users. I want to be perfectly sure that all ...
0
votes
1answer
48 views

Is this SQL schema normalized according to 3NF?

This schema is for a sports statistics/data app Note: Pink background = string/char/varchar Yellow background = int/tinyint Green background = dateTime bold column = PRIMARY key id_* = FOREIGN ...
0
votes
1answer
18 views

Spliting tables with *almost* same values

I have different kind of documents which have common fields (not all of them, but most) and I thought to put them in the same table and use ENUM to differentiate them. Then I realized that if have ...
0
votes
1answer
54 views

Parent/Child table design?

Lets say I have a table to hold Tasks and then I have a table to hold Sub Tasks, is it better to break Tasks and Sub Tasks into separate tables or keep them both in the same table with a possible ...
0
votes
2answers
37 views

Creating a database with only MySQL command line?

The linux server on which I'm attempting to create a MySQL database has many difficult to work with permissions. My supervisor has tried to install MySQL Workbench on the server, but has been unable ...
0
votes
2answers
639 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 ...
0
votes
2answers
68 views

Split date time, with only time, into minutes and seconds

I'm creating an Access database from an excel file that contains metadata about vhs tapes and DVDs. The person who created the excel file had the running times as a date/time field in minutes:seconds. ...
0
votes
0answers
24 views

Schema design for files

I'm implementing a logical schema for a (PostgreSQL) database that will need to keep track of large files that have been uploaded via a web interface into a local filesystem. At present the only ...
1
vote
0answers
415 views

How do I auto-fill data in Microsoft Access 2003?

I am creating a Purchase Order Form at work using Microsoft Access 2003 so that it can be saved and archived in a database and reduce paper costs. These are my current dilemmas: I am unable to ...
1
vote
2answers
2k views

is it possible to create a form in the intranet that can be stored in a database?

I am trying to create a form for my companies intraNet site. The idea is as follows: An employee wants to make a purchase, so they will go to the appropriate page in the intraNet They will fill out ...
1
vote
1answer
59 views

3NF Decomposition - I'm not sure about this example

I am trying to make sense of an example of 3NF decomposition using the 4-step algorithm mentioned by Ullman here, but I'm not understanding what my lecturer is doing with the last step (or, worse, I'm ...
1
vote
1answer
53 views

Restrict two specific column values from existing at the same time

I have a PostgreSQL example table where at most one row that is not of type 'c' should be allowed. I would appreciate any help creating a constraint that will enforce this. CREATE TABLE example ( ...
1
vote
2answers
160 views

Messaging Database - How to handle multiple recipients

So I am trying to develop a relational database (I'm using MySQL, planning on a Java front end) where I have 3 tables (People, where I store names and relevant personal information... and Messages ...
2
votes
2answers
55 views

Give every user 3 default 'bookmark' entries

I've got a table users and a table bookmarks. The table bookmarks obviously contains pages the user wants easy access too. But, there's a new requirement now: every user gets 3 unmutable bookmarks. ...
0
votes
0answers
42 views

Struggling with normalisation (database design critique)

I'm relatively new to database design and have been reading up a lot on best practice, and I'm starting to design a schema for a new application that will be developed and I am struggling with a few ...
47
votes
11answers
8k views

Files - in the database or not?

What is the best place for storing binary files that are related to data in your database? Should you: Store in the database with a blob Store on the filesystem with a link in the database Store in ...
0
votes
4answers
285 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 ...
1
vote
1answer
62 views

How to design a database that tracks sports player's positions

I'm building a database for a sports (ultimate) tracking program. Basically, the "raw data" for the program will be the positions and IDs for all the players on the field at one time. But the way I'm ...
1
vote
1answer
24 views

Relying on expected data

I'm relatively new to Database Design and I wanted to know the disadvantages to a particular decision I have made in the design of a database for a project. I don't think it will have an effect on the ...
2
votes
1answer
387 views

Relationships between subtypes of an entity

I have a very big (hundred of milions rows) table which represent an entity (event) having many subtypes (different kind of recorded events). Each row is identified by an id (obj_id) and has an ...
0
votes
1answer
23 views

Optional oneToOne relations and criteria field

Introduction: Visitors can fill reports on my website. Those report can either be filled by a legalPerson or a naturalPerson. Constraint: I don't like empty fields and I would like to normalize as ...
0
votes
1answer
280 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 ...
1
vote
0answers
83 views

“Replicate” Table structures with sp_addscriptexec

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 ...
1
vote
3answers
217 views

Heterogeneous ordered list of value

I have the following object model: class A { List<Thing> orderedListOfThings; } interface Thing { } class X implements Thing { int attr; } class Y implements Thing { String ...
1
vote
0answers
63 views

Conceptual model vs Logical model vs Physical model

I'm doing a work about database, and now I need to show three different images, one image with the conceptual model, other with logical model and other with physical model of a database. I'm looking ...
2
votes
1answer
65 views

Conditionally join table

I'm new to database design and have designed a database that seems fine for the application but looks like it has a major red flag to me. I have a master table which is then joined to another table ...
1
vote
2answers
42 views

Store n:m data with most n:1 tuples

I have these tables: create table data ( id int identity not null, ref int not null ); create table reference ( refid int not null ); with ~2 million rows in data and ~200k rows in ...