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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Data Compression Through Base36 Encoding

I'm trying to store a lot of large numbers that truncate when stored as INT values. Unfortunately they are too large for this type. I'm thinking about using Base36 encoding to accomplish this. Are ...
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Plural vs Singular Table Name

How should I name my Tables when creating a new database? Singular: Client or Plural: Clients?
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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 ...
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Would it be considered as a bad practice to have multiple nullable FKs on a table in SQL Server

On my database structure in SQL Server, I have 3 types of products which requires different information about the order. So, I created one Customers table and three different orders tables: ...
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Is there a standard implementation of a Users Database?

I need to implement basic personalized user functionality for my website. Is there a standard structure for databases of this type? Like is it common practice to have all user info and data in a ...
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How to find parent rows that have indentical sets of child rows?

Suppose I have structure like this: Recipes Table: RecipeID Name Description RecipeIngredients Table: RecipeID IngredientID Quantity UOM What are some good ways for ...
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How to have a one-to-many relationship with a privileged child?

I want to have a one-to-many relationship in which for each parent, one or zero of the children is marked as a “favorite.” However, not every parent will have a child. (Think of the parents as ...
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What are the performance considerations between using a broad PK vs a separate synthetic key and UQ?

I have several tables where records can be uniquely identified with several broad business fields. In the past, I've used these fields as a PK, with these benefits in mind: Simplicity; there are no ...
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690 views

Should a log table get an id field or primary key?

I have a log table that captures the datetime stamp of when certain files were exported to another system. The exportedLog table currently has three fields: id (primary key) messageId ...
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Are there any good reasons for keeping date and time in separate columns?

I'm trying to understand our software vendor's decision to keep date and time in separate columns. For example, when the row was created or updated. Both time and date are DateTime columns. We are ...
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Concept of Schema in PostgreSQL

I am not able to understand concept and usage of schema in PostgreSQL. I have no idea how it can affect my database design. Why should I use it? Can it affect me in future if I decide to not think ...
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Survey database design: associate an answer to a user

I'm doing the conceptual model for a survey database. The goal is store the answers given by users (it going to be an Android app). I have three entities: user, question and option. A question will ...
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335 views

Clustered indexing is now must - why?

Earlier, there were non-conclusive to me debates/discussions on whether to (always) engage/avoid clustered indexes. Well, I understood that they are to be used sometimes with proper + specific ...
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Database behind a Multilingual User Interface

This question is about an issue somewhat more complicated than the one which has already been addressed in these old questions, all of which are duplicates of one another: Suggestion for database ...
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Are there opensource hierarchical database management systems

I was looking for a hierarchical database management system and the only one i came across was IBM's ims.Are there opensource systems that one can use?.
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756 views

How to structure a model to properly and efficiently represent tree-like data on relational databases?

Based on Traversing tree-like data in a relational database using SQL question, I would like to know how the way regularly used to describe tree-like data on relational databases considering physical ...
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173 views

Arbitrarily ordering records in a table

A common need when using a database is to access records in order. For example, if I have a blog, I want to be able to reorder my blog posts in arbitrary order. These entries often have lots of ...
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451 views

Proper technique for storing users event data

I am mostly a self-taught when it comes to database designs. I am posing this question because I have settled on this common structure, but am wondering if it is the most efficient or 'industry ...
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460 views

Database Design - different objects with shared tagging

My background is more in web programming rather than database administration, so please correct me if I'm using the wrong terminology here. I'm trying to figure out the best way to design the ...
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Store a formula in a table and use the formula in a function

I have a PostgreSQL 9.1 database where part of it handles agent commissions. Each agent has his/her own formula of calculation how much commission they get. I have a function to generate the amount of ...
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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 ...
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886 views

Appropriate multi-language schema, or overkill?

UPDATE 2: I've actually ended up using this, and it's great after a couple tweaks. Here's my post on its actual design, and in action: http://tim.hithlonde.com/2013/lemon-schema-works/ I am building ...
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294 views

Can I losslessly decompose this table?

I've stumbled across a database design problem that's out of my league, and my go-to DBA guru is off on fire drills. In essence, I have a table with the following primary key: child_id integer ...
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177 views

Choice- or ids-list- field representation

I wonder what is the best way to represent a user setting that could either take a value from a set (such as 'High', 'Medium' or 'Low') or be a list of IDs from another (or the same!) table (Many to ...
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Design Pattern - One of Many Parent Tables

I come across a situation in database quite frequently where a given table can FK to one of a number of different parent tables. I've seen two solutions for the problem, but neither is personally ...
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How can I make my database more concise?

I am writing an application for Android using SQLite (backed by ORMlite if it matters). So far I'm in the conceptual stage and working on the database design. The database is being designed to contain ...
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SQL Server: query performance (search 2 million rows)

Got an interesting one for all of you SQL guru's out there. Now this search is only taking a couple of seconds, but it's quite intensive and there must be a better way. Maybe I'm expecting too much? ...
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310 views

Could Stack Overflow run on SQL Server Web Edition?

I am starting a new web venture that may need to scale to a high number of users. I am confident with the SPLA licencing for SQL Server Web edition, but want to know if I will need to factor in ...
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757 views

Best way to document database mappings for migrations

I'm working on a project that includes mapping database elements for a migration and I wanted to know what tools others were using to do this? Excel is a very flexible way to document simple ...
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333 views

Best relational database structure for this data

I'm in the process of creating a database scheme for the following scenario: There are users Users have roles (such as "Developer" or "CEO") Roles have applications (such as "Topdesk") Applications ...
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How does using separate schemas affect SQL Server 2008 performance?

I want to use separate schemas for objects with different purposes in our SQL Server 2008 database. Right now we use a fairly mind-numbing naming convention to indicate the purpose of a table or ...
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81 views

Which schools are known for graduation level database research?

Which schools across the world are best known for research being carried out in database field in recent times?
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SQL Server database design for “archived but available” data

We have this large database (>1TB) that we intend to "shrink". The database revolves around one main entity, let's call it "Visit". For discussion, let's say it is a database for a medical practice. ...
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Performance of query with a range condition and order by

We have the following table (in SQLite on Android) which a tree structure (Nested Set model) of words and their frequencies: lexikon ------- _id integer PRIMARY KEY word text frequency integer ...
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Designing Simple Schema for Disaggregation of Demand Forecast

I am doing a simple database design task as a training exercise where I have to come up with a basic schema design for the following case: I have a parent-child hierarchy of products (example, Raw ...
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Is there any good tool for making Database Design and Prototypes?

I would like to have a good tool for designing the Database Schema with all the tables, columns, data types and relations. Today I mostly do this with pen and paper but I would like to do it in a good ...
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Importance of ER Diagrams

I am a student and I am developing several projects as a part of my academia. While developing the database for one of the projects, we came across a situation where we thought about whether ERD is ...
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One Big Database vs. Several Smaller Ones

We have a situation were we can (A) deploy instances of an applications in one MySQL database using table prefixing or (B) use different MySQL databases for each instance of the application, for e.g., ...
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Purpose of IDs in a User Table Database

In a table, such as a user table, where there will only be 1 row with a for any particular user, why have an ID field, let alone as the primary key?
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What is the name of this schema pattern

Its been a few years... but I've run into a problem-set that reminds me of a schema design pattern and I'm trying to recall the details. Essentially, the pattern consists of one database which is 3 ...
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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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Sharing a single primary key sequence across a database?

Is it an acceptable practice to use a single sequence as a primary key across all tables (instead of a primary key being unique for a given table, it is unique for all tables)? If so, is it ...
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Is there a tool to check if my database is normalized to the third normal form?

I learned about normalization recently, and understand how important it is when implementing a new schema. How can I check if my database is 2NF or 3NF compliant ? Manual review is a sure option, ...
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Is that a good idea to use one database for 50.000+ shops?

I know Shopify use only one database for all shops. But how can they handle their database with such big data? Is that a good idea to use one database for 50.000+ shops?
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Is one-to-one relationship normalized?

Consider we have a large set of statistical data for a record; e.g. 20-30 INT columns. Is it better to keep the entire set in one table as they all belong to a record OR creating a another table ...
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15k views

Matching single column against multiple values without self-joining table in MySQL

We have a table that we use to store answers to questions. We need to be able to find users that have certain answers to particular questions. So, if our table consists of the following data: user_id ...
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Fact table foreign keys null?

I am new to data mart design and need to clear a few concepts. I have read up a bit on dimension modelling where I see that fact tables store foreign key references to dimension tables. Now suppose ...
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Can this business logic be enforced by a conditional database constraint?

I am trying to duplicate the business logic embodied an intranet C# web application in the database so that other databases can access it and work under the same rules. This "rule" seems difficult to ...
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889 views

Database for building a realtime analytics system

I want to build a system similar to Google Analytics (only used for internal use, less traffic and less feature), and mainly focus on Real time counting of unique URI visit/PV by different ...
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Dynamic contacts database

I'm trying to create a database for contacts. I must have many categories for every contact, like Home, Office, Emails, Phones. In every category one can add more than one value. Also the categories ...