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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Record versioning and promotion

Let's say we have this hierarchy: -World --USA ---WA ----Seattle -----Downtown ------1st Ave -------945 1st ave ------3rd Ave ...
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554 views

How can a database be normalized when an optional field causes denormalization?

Suppose you have a warehouse full of widgets. Each widget in the warehouse is stored in a specific identifiable location within the warehouse. You might have a schema which looks like this: A ...
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40 views

dimension table with “like” condition

In an effort to scale some existing code, we are removing logic from CASE statements and putting it in dimension/lookup tables. Thus instead of CASE WHEN 'F' THEN 'Female' WHEN 'M' THEN 'Male' is now ...
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Usage of foreign key when the referenced table data will not change

I have to design a table where user has 10 fields and 6 are dropdown. Some are single selections and some multiple. Dropdown data is supposed to change very rarely. For e.g., the user is presented ...
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2answers
671 views

Is there a good reason to store big text data outside database?

I was analyzing my MySQL database performance and found that tables containing text fields are just huge, larger than 1Gb. This data is only used when loading single record (like article or blog ...
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2answers
3k views

MySQL Workbench connect to MS Access

I have a .mdb file on my computer that I would like to convert into a MySQL Schema and I have found that there is a migration tool within Workbench. However it doesn't seem to allow you to connect to ...
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63 views

3nf but waste more storage space

I have a table which has three columns: account, idNumber, and position. The account and idNumber are unique. Here is my thought to analyze and I don't know whether it is right or not. account is ...
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1answer
1k views

Database design: Two 1 to many relationships to the same table

I have to model a situation where I have a table Chequing_Account (which contains budget, iban number and other details of the account) which has to be related to two different tables Person and ...
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159 views

When to split a large table

I run the SQL Anywhere DBMS, and we have a table of about 10 columns(normal text, timestamps etc). However, in my use-case, every single day, the table gets 2160000 new rows. It's also crucial that ...
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40 views

Table Design for user-specific and user-agnostic criteria

I want to design a table that is general enough to accommodate an increasing number of achievements as I come up with new accomplishments to reward. Initially, I thought to design the table as ...
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1answer
254 views

Time series data for ad platform

I am trying to figure out how to store time series data for an ad platform I am working on. Basically I want to know some strategies/solutions for storing billions of rows of data so that I can ...
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1answer
458 views

Database table design question

Firstly, database novice here. I'm trying to create a system for processing Sales Orders into Purchase Orders and then split the Purchase Order into Shipping Containers. The systems needs to be able ...
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2answers
507 views

Recommendation for mySQL table structure (no code)

I need some advice on how to layout the tables for a mySQL database. I will first describe what I am trying to do: I have a table for users. (This covers basic info for now) A user will select a ...
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92 views

When is it worth it to use Triggers and stored procedures/functions? [closed]

As an example, lets say I have a forum application and for every topic that is created, I have a trigger that fires a database function creating a post.(lets assume we have a topics table and a post ...
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38 views

Are all matching indexes (indices) searched for a query?

If I have multiple indexes that include a common attribute - will each index be searched upon a query involving this attribute? Or is only one index searched?
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205 views

Database Design: separating reusable & instance data

I'm developing an app which is basically a collection of checklists that have to be processed. I obviously need a database in which the information has to be stored. I just can't wrap my head around ...
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1answer
268 views

Where and how to store my weird datamart

I could really use some help here. Here's my situation. I'm building a datamart in SQL Server 2005, which will furnish a single report (for now). We have 26 clients (medical organizations) that ...
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1answer
91 views

How to share resources among accounts?

Using google doc, I am able to share my documents with others. I wonder how they implement it underlying in terms of DB design? The simplest way I imagine is to use a joining table which keeps a ...
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1answer
103 views

One database or multiple referencing one?

Database design: one database or multiple databases, which is best? We have a database which has about a 100 or so tables, accessed by about five different applications. Five different applications ...
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1answer
129 views

Multi-variance products

My current system houses different variants of Products in different tables; Productgroups Productcolors Productsizes Productmodels Products can reside under 1 Productgroup and can have ...
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1answer
92 views

How to “swap” out production tables

I have a MySQL table that holds a few thousand records which go out of date very quickly. A few times a day we run a slow process which needs to pull data from multiple sources and re-populate the ...
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142 views

Using a keywords table with multiple other tables

Using MySQL I need help determining how to model a Keywords table to three different tables (Products, Certifications, and Exams) - I have included my model which is using what I refer to as ...
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2answers
854 views

Can a surrogate key and a primary key be in the same table?

For example we have: Surrogate key: ABC123 Primary key: 1 Name: James Is this legit in a Data Warehouse table?
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2answers
116 views

notes / description string in another table in a relational database

I'm primarily a non-database developer, however I am familiar with normalization techniques. A coworker was suggesting that it is correct for a table to store 'description' and 'notes' as a foreign ...
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Table design when one data is dependant of another and the second one has repeated values

I have a products, and subproducts. Like: Product Identifier - Product Name - Subproduct Identifier - SubProduct Name 1 ProA 1 SubProA1 ...
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1answer
167 views

Need help to design model with multiple rights

For a website, I have multiple elements that need to be moderated by many different users. Until now, I have always used Role-Based Access Control (RBAC) model but I want a more flexible model. I ...
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1answer
43 views

How to link several tables?

I'm a newbie at Database Designing. What I want to do is perform several actions at once. I have a main users table which holds all the data for a user at a website. Then I have a primary key as the ...
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1answer
177 views

What is the meaning of this anomaly warning message?

I have run an analysis with SchemaSpy. The tool gave me a warning message for two tables. The warning message is: Tables with incrementing column names, potentially indicating denormalization ...
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3answers
144 views

pros/cons of different ways to store whether a record is one of two options?

I am trying to store whether an address is a Work address or a Home address. There will never be another type of address. I'm wondering what the pros/cons are of the different ways to store this, ...
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1answer
47 views

How should permissions for anonymous users be modelled?

I'm designing a web application. There will be users who log into the site, but also anonymous, non-authenticated users, i.e. any member of the public who accesses the site. Users will be assigned to ...
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1answer
86 views

Index optimization

I'm building a 'tag' system for my blog posts. Currently my tags table has columns tagid - MEDIUMINT NOT NULL AUTO_INCREMENT PRIMARY KEY and tag VARCHAR(30) NOT NULL UNIQUE. And I have another table ...
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660 views

How to design this database to avoid cyclic dependency?

There are two tables: User Address User contains a reference to Address. Address contains the columns CreatedBy and ModifiedBy, which is reference to User. How do I design this database to avoid ...
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4answers
2k views

Database design - People and Organisations

Databases are not my primary skill and I am finding I need some assistance please. The software we are building has "Customers". The Customer could either be a Person or an Organisation. I really ...
5
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1answer
119 views

Many:Many with Shared Relation

I'm modelling data with multiplicity like this: Each Composition/Anthology related pair must share a Composer. Also, each Anthology must contain at least one Composition. How would you recommend I ...
2
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1answer
110 views

What are the risks for logging across databases via a trigger?

I've searched for this online and had mixed or unclear responses, and after posting on superuser, was directed over here. On SQL Server 2005, we currently log certain table changes via triggers using ...
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3answers
153 views

Database Design Confusion

I am making a Phonegap based ERP solution for school in which every school can configure their own school individually and can manage the whole school from that single application, in which a main ...
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1answer
238 views

How to handle “many columns” in OLAP RDBMS

I have a fact that has around 1K different numerical attributes (i.e. columns). I would like to store this in to a column-oriented DB and perform cube analysis on it. I tried to design a star ...
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1answer
2k views

Oracle database created whats next? Create Schema or Create Tablespace?

I'm a programmer that's being thrown to the DBA/Sysadmin island all by myself with a volleyball that I named Wilson. I'm trying to survive here. I'm supposed to create a database for an application. ...
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1answer
336 views

Table for optional parent/child relationship

Assuming we have the following table: Item, Parent, Child and Parent is the parent of child. The item can either belong to a parent or child and not both. I have other tables that are similar to ...
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1answer
125 views

What is the correct model for related tables with millions of rows?

I need to create a question and answer tables that will have millions (maybe billions) of rows. The current model is: Question Table id_question (PK, auto increment) id_user question_content ...
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2answers
400 views

Is it ever a good idea to denormalize for integrity?

I'm using Postgres 9.2 to develop a quiz app, in which I present the user with a series of problems and record their answers. These problems can take a variety of forms - they might be multiple ...
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2answers
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checking number of occupied occupied neighbours [closed]

Assuming a pixel grid with x and y of the size 1000 over 1000. In each iteration\run, using a random number generator, certain cells will be marked as occupied. Those cells will be written in a SQLite ...
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1answer
564 views

Database for opening times of locations

I'm designing a database for opening times and created this solution. The specifications of the database which will be a MySQL are, that a location have standard opening times in a week and can ...
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1answer
469 views

Defining system scope and boundary

I have been given a homework task where I am to create an ER model of a database from a set of client requirements. Another part of this task is to create a diagram that shows the scope and boundary ...
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1answer
166 views

Separating tables vs having one table

At the moment I have a table setup that looks somewhat like this: create table tbl_locationcollections ( id int(11) PRIMARY KEY IDENTITY, --(Primary Key), name varchar(100) not null, ...
2
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1answer
103 views

How to enforce a nullable foreign key?

I have a relation between two tables. The foreign key table can have a row related in the primary table. There's a way to enforce the value of the FK column to be NULL or one of the values of the PK ...
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1answer
24 views

Which of tables key to reference?

MySQL. There is a table users with autoincrement primary key id. There is also a table employees (every employee is a user but not vice versa). The employees primary key is userid. The field userid ...
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1answer
40 views

Relational Database tables

I have a table Player where playerID is the primary key. Then I have a table Game where gameDate is the primary key (of type DATETIME). Each game is played by 2 players and each player can play many ...
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1answer
118 views

One to at most one relation or multiple null columns?

I have a table with many attributes that can be grouped in logical groups, and thus the idea of put this attributes in separate tables seems attractive. The logical groups doesn't represent entities ...
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1answer
153 views

Is it better to use multiple one-to-many relationships, or polymorphic?

I've got the following tables: Clicks table Websites table Ads table Both Ads and Websites have many Clicks (i.e. both models have a one-to-many relation with Clicks). In such cases, is it better ...