For questions about structuring the data within a database. How to lay out tables, whether to use a relational DB or not, etc.

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3
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1answer
155 views

Database Design - Optimise Relationships

I am about to embark on a redesign of an application, one where querying the database is particularly annoying. I intend to redesign the database as much as possible but the data shape cannot change ...
1
vote
1answer
70 views

SQL Table Design Modification based on data roles or implementation convenience?

I've got an existing SQL table structure that looks like this: Orders - order_id - organisation_id - [all the rest of the order data] Organisations - organisation_id - [all the rest of the ...
0
votes
1answer
140 views

Google Datastore and deep records

I'm in the beginning of creating a website that uses Google Datastore to store information related to clients and I'm curious if the record is too deep for NoSQL or if I'm fine. Essentially I'll be ...
1
vote
1answer
811 views

Mongodb array vs object

New with Mongodb, and I'm not sure what implications or benefits there are between the use of an array vs an object. So.. As above what are the implications and benefits between the use of arrays ...
0
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2answers
167 views

How to salvage a business model from a mismatched database?

There is an application that involves billing enterprise customers for the services their customers utilize. The database schema does not properly reflect the business model. For instance, on a given ...
4
votes
4answers
554 views

In an online questionnaire, what is a best way to design a database for keeping track of users all attempts?

We have a web app where users can take online exams. Exam admin will create a questionnaire. A questionnaire can have many Questions. Each question is a multiple choice question (MCQ). Let's say ...
3
votes
2answers
324 views

Single Responsibility principle VS KISS principle

Let's assume the modeling of User model in a context of a social network. User concept is composed of two notions: Authentication elements like userName/Password/Email etc... Extra data information ...
2
votes
4answers
494 views

How to genericize foreign key references in table?

I am trying to design a table to store references to multiple tables as a "target" of the item in each row. An example should clarify what I am trying to do: Imagine you have 4 tables (images, ...
2
votes
3answers
1k views

Is there a better way of handling access control logic instead of it being in the UI?

Through most of my dev experience, I've never had to deal with much variety of access control architectures. They've all been pretty straight forward: Group [Create, Update, Delete] - User 1 ...
0
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1answer
112 views

Keyword Collection, ManyToOne or OneToMany relationship?

I hope this is the right place for this type of problem. An Object of my class Movie can have several keywords ( like 'fight club', 'brad', 'fincher'), and be part of different categories (like ...
1
vote
1answer
3k views

How to model/structure data that contains parent/child relationships for the same entity?

I think it is just my thinking that is off here. Suppose I have two entities: question and choice. A question can be a parent or child, or both (in relation to other questions). It seems that this ...
2
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1answer
2k views

Representing a parent/child hierarchy in a Relational Database

I am working on an application that connects to another application (Quickbooks) using an API by sending/receiving XML requests/responses. I am able to work with the data in the XML response and load ...
3
votes
3answers
299 views

Design pattern to dynamically create patterns found in a list of links

Can anyone help me think of a way to dynamically generate the patterns section of a tool I am creating? I'm not sure how to store and generate these "patterns" dynamically. What the program does is ...
6
votes
2answers
2k views

Handling subscriptions, balances and pricing plan changes

Preamble My aim is to create reusable code for multiple projects (and also publish it on github) to manage subscriptions. I know about stripe and recurring billing providers, but that's not what this ...
3
votes
2answers
206 views

Referencing countries via Foreign Key Constraint

To make things simple to explain: I've got two tables: Table1 and Countries. The Countries table contains a nice flag and some information, such as DisplayName, the ISO3166 ALPHA3 code and the phone ...
12
votes
3answers
2k views

General thought process for “How would you build this website/app” interview questions

I've collected a bunch of interview questions like "Describe how you would design a photo album application", "Describe how you would design this particular feature of this particular website" (e.g. ...
3
votes
2answers
2k views

What is the best practice for saving TimeZones in the database?

We want to start collecting timezones for each of our addresses in the database. What is the best practice to store the timezones? How would you go about acquiring timezones for the existing address ...
0
votes
1answer
119 views

What are some database designs that support lineage tracing?

Environment PostgreSQL 9.1 Java Problem I'll try to illustrate the problem here as simply as possible: I'm trying to record the following relationship: Node 1 => Node 2 => Node 3 Where Node 1 ...
1
vote
1answer
88 views

What common apporaches exist for database versioning for a feature driven development?

It's not clear how data consistency is provided for different branches. We have a large knowledgebase which is filled by the experts and delivered as updates to our clients. This data is also used ...
0
votes
4answers
233 views

Create a database for database tables

I'm working on a project where I have to give users the ability to build their own tables, each user can create more than one table. (the type of all data is string). The user can create a table and ...
0
votes
3answers
291 views

SQL Server + database design and non mandatory fields

I am developing an app which allows a user to upload a maximum of 20 photos, the straight forward way is of course adding 20 columns to my database table but if the user only uploads 1 image, the ...
4
votes
3answers
315 views

What is the best approach for overriding fields in a database?

I have a database that contains projects and each project contains many samples. I want a project level threshold value, to trigger highlighting when a field on the sample is above this threshold. I ...
8
votes
5answers
607 views

Storing a re-orderable list in a database

I'm working on a wishlist system, where users can add items to their various wishlists, and I plan to allow users to re-order the items later on. I am not really sure about the best way to go about ...
1
vote
1answer
491 views

Multi-user Configuration Settings design

I am designing a flexible and extensible way to store configuration settings for users. Database Table Design: ╔═════════════════════════════╗ ║ ConfigurationItemDefinition ║ ...
12
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6answers
1k views

In plain English, what is a database index most similar to? [duplicate]

Setup: Suppose you are teaching an introduction to Databases class, the students are CS students that have a working knowledge of tree structures, how they can speed up searches, and have probably ...
0
votes
3answers
182 views

How to maintain user relationship when user unfollows another user

I have a table of user relationship which stores who follows whom, the table structure is as follows -id -follower -following when someone follows any other user, I add a record with follower user ...
-1
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1answer
173 views

Storing User Form Data

I am trying to come up with a data schema/methodology for storing the data collected from various different user application forms. All forms contain the basic info like name, address, etc but then ...
2
votes
1answer
106 views

How do I manage multiple relationships from a software design perspective?

How do I go about managing projects when there are two fundamental relationships that need to be maintained? The most obvious example that I can think of would be a firm doing some kind of ...
3
votes
2answers
221 views

Bayes filtering and data storage with expansive data sets

I am looking to write a Bayes filter that will act as an indicator of topic for a number of topics with a variable number of sources. Given a really big number of RSS feeds and here really big might ...
1
vote
3answers
834 views

Should lookup tables enumerating strings have an integer primary key?

When I learned relational databases, the prof said that one would "almost always" want an artificial int as the primary key in a table, but did not specify what the exceptions are. At some time I ...
0
votes
1answer
127 views

What is a good design for a container, assignment and items

------------- 1 * -------------- * 1 -------- | Container |--------| Assignment |-----------| User | ------------- -------------- -------- ^ ...
2
votes
3answers
460 views

Using a database for each module in a system [duplicate]

I was reading this question: I was trying to standardize and modularize some functions (Email Management Module, CMS Module & etc) by implementing a 3-tier architecture concept where each ...
1
vote
2answers
471 views

Why OTServs have an item cloning problem if the server crashes? [closed]

OTServs are open source MMORPGs with a huge community. Mostly all of them have a serious problem: if the server crashes, people can clone items. This is a dirty trick that can be executed because the ...
1
vote
1answer
833 views

NoSQL (Azure Table Storage) RowKey design for ordered data

I store large quantities of GPS data in storage tables. Each partition can reach up to 1 million entities. Each GPS entity that is inserted into the table is actually sequential to the previous data ...
5
votes
6answers
4k views

Why is the usage of string keys generally considered to be a bad idea?

This has been bugging me for a while. Most of the time, when it comes to storing data in structures such as hashtables, programmers, books and articles insist that indexing elements in said structures ...
1
vote
1answer
128 views

Azure Storage Table design with multiple query points

I have the following Azure Storage Table. PositionData table: PartitionKey: ClientID + VehicleID RowKey: GUID Properties: ClientID, VehicleID, DriverID, Date, GPSPosition Each vehicle will log ...
6
votes
1answer
125 views

Ledger or log design for a point-based system?

Right now creating a new service that will integrate into our company's existing platform. The service will be responsible for tracking "points" that a user can generate over time through certain ...
1
vote
1answer
631 views

A multi tenant data architecture

We are at a planning & redesign stage of our loyalty card application. As it is understood it will be a multi-tenant application. And I need to take your thoughts. Here are the some key points we ...
1
vote
1answer
334 views

Table scaling with partitions or with separate databases?

Let's say I have a table (let's call it BigTable) which could experience 5,000,000 INSERTS per day (with possibly just as many SELECTs). Each row inserted is about 50kb. These daily INSERTs are ...
3
votes
2answers
139 views

Does this situation call for well specified associations, single table inheritance, or polymorphic association?

I'm building a web-app where users can keep track of who owes whom money. I have users and debts. Given a user I want to be able to find out all the debts to other users, and all the loans to other ...
6
votes
4answers
7k views

Better way of storing key-value pairs in the database?

I have a C#/SQL Server program that sometimes needs to store data. The data could be a response from a web service, a result of a database query, or any number of other things. There's no way of ...
0
votes
2answers
423 views

How to improve database schema with different n:m and 1:n associations between users/tasks/comments/attachments

I'm trying to build a database for an upcoming Ruby on Rails webproject. There will be 4 tables minium: tasks, users, attachments and comments. And 1 table to join the n:m relations (tasks <-> ...
7
votes
3answers
1k views

How should I represent an enumerated type in a relational database?

I am working on developing a relational database that tracks transactions that occur on a device I'm working on for my company. There are different types of transactions that could occur on the ...
2
votes
2answers
171 views

Should database-models (conceptual or physical) be reviewed by DBAs?

Where I work, new applications that are being developed that will use their own relational database, must have their database-models (conceptual, then physical ) reviewed and aproved by DBAs. Things ...
3
votes
6answers
582 views

Should a database table(s) structure match its intended data structure(s) in the logic?

This question branches out of this question, What are the differences between algorithms using data structures and algorithms using databases?. The General Question Should a database table(s) ...
3
votes
4answers
481 views

(Dis)advantages of datetime vs. long in globally used applications [closed]

I am currently designing a web/mobile application the bulk of whose users will be distributed across the different U.S. time zones with a potential of scaling up to other countries and time zones as ...
8
votes
7answers
737 views

Design Parts DB

I'm developing a tool that handles (electrical) parts. The parts can be created, viewed, modified, deleted, grouped and so on... In order to make this question useful for future visitors I like to ...
1
vote
2answers
1k views

Alternatives to sql like databases [closed]

These days computers usually have 2GB or 4GB memory. I like to use some secure client server model, and well an sql database is likely candidate. On the other hand I only have about 8000 records, ...
1
vote
1answer
389 views

Storing revisions of a document

This is a follow up question to my original question. I'm thinking of going with generating diffs and storing those diffs in the database 'History' table. I'm using diff-match-patch library to ...
4
votes
3answers
8k views

When should we use weak entities when modelling a database?

This is basically a question about what are weak entities? When should we use them? How should they be modeled? What is the main difference between normal entities and weak entities? Does weak ...