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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Storing and querying rolling data in PostgreSQL

I have a large quantity of weather model data being put into a PostgreSQL database. The machine has 8 cores and 16 GB of RAM. I'm running PostgreSQL 9.3 with PostGIS 2.1. Each table will have a ...
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211 views

Mathematical method for spotting irregularity in numbers flow

I am trying to build an engine which is going to predict orders for items inside shop. Three main variables are: Time-dates (x-axe etc 1.1.2013,1.2.2013 etc I do calculation one per day) Available ...
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123 views

Replicating databases for local and cloud instances

Forgive me if this is an inappropriate place for this architectural question but I'm not sure where it best fits in the StackExchange family. I have been tasked with developing an online/live auction ...
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153 views

Database describing databases and references to tables

Context The company I work for makes a number of different softwares each with its own database. As they're all about related things (accounting) a good amount of data is theoretically the same among ...
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331 views

How to design a database for financial bond prices?

I have following flat file table composed of bond deal names and asociated prices. Each deal name is identified by its unique CUSIP and ISIN codes and each deal name is classified with a certain ...
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54 views

Storing URLs in a database

I am thinking about storing URL's in my database, but I am not sure whether the way I use is an efficient way to do things or not. Table name : url url_id (Primary Key & Auto Increment) url_value ...
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28 views

How to store a 64-digit key of alpha numerical values into MySQL Database

I am student studying in Database Administration (first year), one of our task requires a to design a login form for corporate and regular users. Below are the requirements for the username and ...
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39 views

With SSD's and in memory tables, does a snowflake schema become preferred over a star?

With SSD's being very fast (reducing the overhead of joins), while more expensive (increasing the cost of redundancy due to de-normalization), along-with a focus on in memory tables (again reducing ...
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82 views

CouchDB and document versioning

I'm currently working on a wiki-esque application using CouchDB and am trying to implement a document versioning scheme. The way I see it there are two ways of doing this: Store each version as a ...
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82 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 ...
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31 views

How do I design a database for different sets of measurements on different subjects?

I'm conducting a research project that consists in sampling different physical quantities on about 30 buildings, most of them single-family houses. Some of those physical quantities will be common to ...
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43 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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50 views

Proper design of routes in Database MySQL

I'am trying to find out the best database design and try to stick with data integrity by using Foreign Keys. But I'm stuck right at the beginning because of limit relations between tables with FK to ...
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93 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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101 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 ...
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230 views

How to model (a many to many) to many relationship

Hello i am facing the following scenario. I have a student table with the following structure. Student id(PK), matriculation number, first_name, last_name, email A student can have more than one ...
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179 views

Problem with Database for survey Questionnaires

Bellow I am showing a sample survey question for woman. I need your help to creating a Database. Description: Top part of the survey Questions are Project Code, Name... etc which is ...
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175 views

Geographic Hierarchies in a OLAP Cube / Data Warehouse

Are the following geographic hierarchies correct? Do any US/Canadian area codes cross state/province lines? Do any US/Canadian counties cross state/province lines? Are there countries with counties ...
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112 views

Two different ON DELETE paths, how do I need to change the schema?

For a project in school I'm designing a website that sells items via auctions. Think eBay, but on the complexity scale of school project. We went through the process of making an ER Diagram and ...
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368 views

How to properly configure pgBouncer transaction level pooling?

What is a good way to determine the number of available transaction connections when using pgBouncer to pool database connections? Also, how should I determine the number of max_connections and ...
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110 views

Digital asset management

I'm working in a company that currently develops Media Asset Management system and now we want to improve our system for document files. I have to search nearly thousand .doc and .pdf files and index ...
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2k views

Schema for an RBAC (Role-based Access Control System)

I want to implement an RBAC, Flat based. I've decided to base my system on the NIST standardization model. Although all fine and well, I have an inclusion to that design. Instead of a hierarchy ...
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435 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 ...
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11 views

Nosql multiple database design to handle sharing scenarios

This question is regarding design of a database in mongodb. The scenario: A user has a drive which he can share with others. Drive has two categories: docs and others. The user has three choices in ...
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What are the different types of binary relationship types?

I'm new to databases and while studying questions on it, I've come across one that I can't find the answer to. Define the three different binary relationship types that are common in relational ...
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26 views

MySQL column type to boost performance

I'll have a table where: userid (link to user's id in users table) foldername (a varchar, max. 260 char) entry (varchar, max. 1024) data (varchar, max. 20kb) Single user will have several ...
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48 views

How do I maintain categories and products of an optical store?

I have a requirement for an optical store. He has various categories like AgeGroup(Kids/GrownUps), GenderGroup(Male/Female/Unisex), FrameType(Metal/Plastic), FrameShape(Full ...
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15 views

Enforce referential integrity for FriendRequest table that has UserA and UserB

I have a table called User that has UserName as a primary key. I want to establish a relationship with enforced referential integrity between User and FriendRequest. FriendRequest has the following: ...
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18 views

reports on history table

Assume Trucks which travel between Cityies. I store the Cityies that a Truck has traveled to in TruckLocationHistory table, if the Truck is passing the City, State = Passed and if it gonna stays for ...
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62 views

How to represent directed graph with multiple parents?

http://dirtsimple.org/2010/11/simplest-way-to-do-tree-based-queries.html provides an algorithm for inserting and deleting from a Closure Table. I'd like to model a similar data structure, except that ...
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66 views

DB Design: Looking for Performance improvement with a Column used in all SQL Queries

I recently got added to a new ASP .NET Project(A web application) .There were recent performance issues with the application, and I am in a team with their current task to Optimize some slow running ...
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60 views

Relational or non-relational database for a system to pass objects on?

hopefully this is the right place to ask this kind of question. I am working on a system that focuses on helping people give away things that they don't use anymore. So, an object typically has the ...
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92 views

How to handle many columns / variable schema?

I apologize in advance in case this question has been asked already. I'm working on revamping a reporting application used within my company. The requirements are: Support addition of new fields ...
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44 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 ...
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91 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 ...
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66 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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23 views

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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93 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 ...
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117 views

Postgresql - How to Convert all Column Names to Lowercase

I have a travel survey with a series of tables (lots and lots of columns) that I exported from MS Access into a postgres database. I've search around a lot for an explanation of how to convert all the ...
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18 views

Modeling for inclusion of two different entities

What I Have I am currently hashing out the data model for an application that will utilize MongoDB. In my setup, users or members (as they are called in the schema) will be created and then assigned ...
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263 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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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 ...
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32 views

Basic Design Question about one to many in a table

Sorry for the basic question but I am new to all of this! Say I have a table named Runs, and each table has Run: id (primary_key) data (String - path to a data file) status timestamp ... ...
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35 views

Second opinion about elimination of possible redundant database column

We currently have a Widgets database table were we track the widgets the company produces. When a widget is produced the widget information is added to this table. This Widgets table contains a Status ...
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30 views

A better model for connecting users to different objects, even efter they cease to exist

I've got the privilege to create a small in-house application for managing todo-lists, although I am not really a developer. (I know some PHP and SQL, and got a chance to prove myself). As my ...
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122 views

Can somebody check this normalisation workings i think i am missing a step or a dependency somewhere

given these two tables: and: I need to first list them as an un-normalised structure(s) then i need to identify the functional dependencies/primary keys. Once i have done this i must represent ...
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95 views

How to join the tables in mysql to get wall messages and comments with name of person ? Only user and his friends messages

I have four tables in my mysql database as shown in the image url provided. I want to select data from the tables without duplication. I want to show messages and comments on wall according to the ...
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32 views

Keys of a relation

I got relation: R = { (ABCDEF) , (A B F -> C, B C -> F, F -> A, F -> B, D E -> E, E -> D)} keys of this relation are: {BCE}, {EF} But i dont get it... why? Why not only {EF}.. it got less ...
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512 views

SQLite Design: Better to have many tables with few columns or few tables with many columns?

I am struggling to figure out the best design for a Sqlite database that will hold data about Facebook pages so that I can calculate benchmarks for how the average Facebook page performs. I have an ...
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107 views

Relation between lossy decomposition and Natural join?

I am confused with the lossy decomposition and natural join. Natural join(with common attribute): only respective common attribute for the resultant table is formed. Lossy: Natural join on tables ...