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
180 views

MySQL DB structure with Main category and several nested sub categories

I am looking to create a set of fields on my webpage identical to what eBay uses on their category selection page when you are selling something. For my purposes I am doing motorcycles, power sports, ...
0
votes
0answers
2 views

How to model mappings at various levels

I'm trying to design the database model for my application and I'm finding it difficult to design the mappings for user access to various entities stored in the database. If access was only ...
0
votes
0answers
9 views

Storing DB credentials in an application source code?

I am making an app which connects to a DB, and the app will have plenty different userslogins. Is it a good design choice to have a specific DB login/password for the application, using which the ...
0
votes
0answers
6 views

Launching an RDS in a private subnet in VPC and access it from a web application

I have setup a VPC which has two subnets. One is a public subnet (I have Internet Gateway attached to it) and the other one is a private subnet.My web application resides inside the public subnet and ...
0
votes
0answers
22 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 ...
0
votes
1answer
12 views

How to predict the growth of a PostgreSQL database

I'm looking for a way to predict growth of the database given its fields, indexes, constraints (as foreign key), number of lines, and so. I searched on Google, but I found only means to determine the ...
0
votes
0answers
21 views

DB design, when to split out into schemas

I am building a storage solution to store important themes/concepts referenced in books. At a high level the system will contain one or more catalogs and each catalog will contain one or more books. ...
3
votes
2answers
32 views

How to enforce the structural constraints of rectangularly arrayed data?

(I'm particularly interested in answers that view the question below as a special case of the question: how should a RDBMS enforce structural constraints that are more specific than "one-to-many" and ...
0
votes
3answers
47 views

How to design database with january-december for every entry [on hold]

Need help for designing my database, I have a table named transaction with columns: tr_id, item, item_cost, item_quantity, total and my problem is: I need to divide the item_quantity from january to ...
0
votes
1answer
45 views

When to use hashtable over binary search tree vice verse for Database Index

Database Index can be constructed using binary search trees (BST) or HashTables , From my understanding so far , HashTables are superior to BST in terms of time taken for searching and insertions ...
0
votes
1answer
103 views

Multiple product attribute inventory database design

i have a database to build based on inventory for my shop. this is the current data that i have put into tables this is the package: this is the product attribute this is the table to produce ...
0
votes
0answers
13 views

How to test if a model is erroneous?

i am trying to realize why the following model is erroneous(or not). i am taking a database course and while i was studying I've found that model.
0
votes
2answers
44 views

What database should I use? [on hold]

I am writing a log analysis program in bash. As part of it, I am compiling a list of known errors, so that I can search and reference those errors as part of the known list. I originally was going to ...
0
votes
1answer
58 views

Create one-to-many to two fields in different table

I have a database where I am trying to figure out how to join a table that contains an object called ModelType. The calibration table contains two fields (EffModel and BkgModel) that are based on a ...
0
votes
0answers
27 views

SQL Server Database is corrupted - how to save it? [closed]

Respected Sir, unfortunately hard disk of my system is damaged, now I recovered my database. but it cannot be attached again to SQL Server 2005 Management Studio. The error is myfile.mdf is not ...
2
votes
2answers
28 views

Schema for storing historical data on shared identifiers

When user account is assigned an IP address, I create a table entry for the account/IP mapping. This data in the table is updated every 5 minutes. Right now I'm only keeping real-time data but I need ...
1
vote
1answer
47 views

Recipe Health risk Database ERD structure

I have these tables: First table(Recipe table), Recipe recipeid(PK,AI) recipename ingredients Second table(Ingredients table), Ingredients ingredientid(PK,AI) ...
0
votes
2answers
50 views

How to break table into two without losing performance?

According to http://stackoverflow.com/a/174047/14731, splitting away infrequently-needed columns frees up the cache allowing faster retrieval of the commonly-used columns. I've got a table whose ...
0
votes
2answers
28 views

Need Help maintaining multiple databases for a multi-tenant application?

i need some information about multiple databases for a multi-tenant application ? I am working on a project in which we are maintaining separate database for every company? The Companies Database ...
0
votes
0answers
42 views

How can I deal with a multi-record type field without breaking things futher? [on hold]

If I remember anything about database design, I think this is a scenario where I'd use a combined key right? So I have. Note: Field1, Field2, Field 3, FieldX; Alert: FieldA, FieldB, FieldC; All of ...
1
vote
1answer
46 views

Does a Key-Value type table still needs a auto increment key?

Suppose that I have a very simple table to store variable-like data, like this: +-----------+-----------------+ | key | value | +-----------+-----------------+ | site_url | ...
1
vote
0answers
47 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 ...
3
votes
4answers
109 views

How do I prove that the act of removing foreign keys doesn't corrupt existing data?

TL;DR: Prove that in practice, the execution of the alter table table_name drop foreign key constraint_name statement does not corrupt existing data. The important consideration is the execution of ...
0
votes
1answer
24 views

Max from 2 columns with priority date col then the seq col Oracle

I have a column xdate, column seqnumber, personID I want 1 record per personID, where it is the most recent xdate max(xdate) if there is multiple same max xdates i want it to look then for the max ...
2
votes
1answer
24 views

Hierarchy for dimensional model

I am trying to model a DW where I have many levels of geography (Neighborhood, District, City, State). I have several demographic data that should be included in the model. These data include count ...
7
votes
4answers
220 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 ...
1
vote
2answers
86 views

Table design for multi-type data

The information model I am modelling from includes an "any type". For example a customer can have zero or more 'entries' each of which can have a number of values. Each value could be a either date, ...
0
votes
1answer
38 views

Building a branched versioning model for relational databases

I am database designer and at my current project I'm implementing versioning capabilities required to concurrently edit rows of data in RDBMS. The project requirements says, that data editing sessions ...
0
votes
1answer
461 views

Efficient way to move rows across the tables?

This is somewhat long question as I would like to explain all details of the problem. System Description We have a queue of incoming messages from external system(s). Messages are immediately stored ...
0
votes
1answer
31 views

Schema for multi-account database

I'm building an app which will have accounts for organisations leading to organisation.myapp.com subdomains for their account access. I'm putting together the schema for it and I have a few ...
0
votes
1answer
353 views

tables for different sources of payments

Selling software products. I have a table "licences". Each software licences is created due to a payment. I am creating tables to accept payments from different sources (e.g. manual or PayPal.) I'm ...
0
votes
0answers
23 views

Minimize table joins in design

Probably didn't come up with the best title, but I'll explain what I'm trying to do. I need to be able to track gym members, trainers, workouts, and gym locations. I've created a simple example below. ...
0
votes
2answers
17 views

Null column for username and password when using Login with *social network*

I want to know what are the conventions for columns like username and password when your application supports login with a third party, like login with facebook for instance. Given the fact that when ...
0
votes
1answer
101 views

Relation between multiple hierarchical taxonomies linked to a single entity

I am working on an online test application which supports multiple choice questions. I have created schema for taxonomy (classification) system to be used with questions. taxonomy(id, name, slug, ...
4
votes
1answer
354 views

Bad Design or Complicated Query?

Problem: For fun I am building a Database for lottery results to get some statistics off of. As of now I am only interested in a Pick 3 style lotto and might introduce more later. How would you ...
0
votes
1answer
28 views

How do I choose primary keys for star schema BI data warehouse?

I am extracting sales turnover data from a Microsoft Dynamics Database into another SQL database that will be used by the BI tool of choice. This data is coming from G/L (general ledger) entry items. ...
4
votes
3answers
805 views

Are there any tools to go from ERD to DB design and vice versa?

I'm learning DB design and looking for some tools, preferably open source software, that could help go from an ERD to a DATABASE and vice versa. For the record, the database i'm using is MySQL.
0
votes
1answer
70 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
14 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 ...
0
votes
3answers
39 views

MYSQL Indexes when looking up on alternating sets of columns

I have a table that looks like: CREATE TABLE `connections` ( `connection_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `service_id` smallint(5) unsigned DEFAULT NULL, `parent_id` bigint(20) ...
1
vote
4answers
124 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 ...
0
votes
2answers
162 views

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 ...
1
vote
1answer
82 views

Enforce referential integrity between two groups of data

I have two sets of records: A collection of rules. A collection of actions to perform based on those rules. What I'm trying to model is something like this: Multiple rules can be grouped ...
1
vote
3answers
119 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
0answers
19 views

Correct Schema Design for form builder? [on hold]

I'm attempting to build a form builder app that allows users to: signup build a form store the data from that form into this db. I have designed the following schema: ...
0
votes
1answer
61 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
71 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
195 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 ...
0
votes
1answer
51 views

Train Fare Database Normalisation

I have a database to normalize. The database has details of train ticket fares. The trains have different fares depending on the distance and I have to store these fares in the database It is not an ...
2
votes
1answer
70 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 ...