This tag is for general database questions; if you question is specific to SQL use that tag instead.

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4
votes
2answers
88 views

best way to attach database structure for an open source project

I have a small project which I want to publish on github. The problem is that my project contains a database. I don't know what is the best way to attach the database structure. I may get the create ...
0
votes
1answer
53 views

Quickly write log entries from http requests in a MySQL database with high performance

When a dataset is saved in the software I use, a http request is triggered (fire-and-forget). Information like the timestamp, the user and the changes made are listed in the GET parameters. Now I ...
2
votes
1answer
485 views

Organising data access for dependency injection

In our company we have a relatively long history of database backed applications, but have only just begun experimenting with dependency injection. I am looking for advice about how to convert our ...
0
votes
1answer
122 views

Would it make sense to have a database table with only one record for tracking site summary stats?

I'm creating a web site that deals with monetary transactions. Users can deposit funds into a wallet and use them on the site. I'd like to keep track of some stats for the web site, like revenue and ...
2
votes
1answer
122 views

Normalization 3NF and BCNF

If I have the following relation R = (A, B, C, D) And the functional dependencies: A -> B, B -> A, CDB -> A, CDA -> B The candidate keys are CDA and CDB. The third normal form says that ...
0
votes
1answer
70 views

Database vs. server-sided scripting language [duplicate]

To keep my question short and to the point, consider this: $relation = $mysql->query("SELECT relation($loggeduser, $requesteduser) AS a")->fetch_assoc()['a']; if ($relation != BLOCKED) { ...
1
vote
1answer
142 views

A very simple database system with JSON

If we need to store some data in a database, but without the need of advanced SQL features, can we use this scheme (written here in Javascript / node.js) : // the DB will be in RAM ! var myDb = {}; ...
1
vote
2answers
85 views

Retry method for generating unique code

In an app, a user can initiate the generation a six-digit alphanumeric code (actually done via Web API). The code needs to be checked against a remote database to ensure it is unique. Other than for ...
6
votes
1answer
302 views

Log to file or to database table?

I'm developing a web application which uses MS SQL for various data: including users, user accounts, user licenses, license prices, invoices. I need to log users' real-time usage of the system, and ...
0
votes
1answer
518 views

Designing a scalable schema for college database [closed]

I am trying to build back end for college ERP system. The system will be based on LAMP. These is the scenario: Colleges have 5 branches There are 4-6 classes in each branch. There are 80 students ...
7
votes
3answers
202 views

How to model and store an entity which has “one or more” values

I'll use C# to design the model to be persisted Let's suppose I have the following entity: public class Episode { public int Id { get; set; } public string Title { get; set; } public ...
4
votes
2answers
117 views

Using audit trail as time machine?

I would like to do SELECT * TABLE t (using data from 1st of march 2012) I already have a nice audit trail of all tables in the database. It basically makes a copy of all rows that change, storing ...
0
votes
1answer
84 views

More than 20 Records Inserted in a Span of 1 Sec

Well, this is not specific to any programming languages. I came across this situation in Android, iOS, PHP and .NET. The problem is many times I come across a situation while building IoT apps, where ...
2
votes
1answer
172 views

Matching algorithms in context of data quality problems

I work for an organization that has lots of databases containing person information. The data quality is poor. One case was a surname I found like this (this is the worst-case scenario): Mark ...
2
votes
3answers
139 views

Best approach for storing huge data

I'll be handling 300,000+ users. Each user (after logging in) will be able to create lets say "folders", in each folder, users will create "name=value,name2=value2,name3=value3" entry pairs. Each name ...
0
votes
1answer
42 views

online database with partial access for clients

I'm trying to come up with an online database that my clients would have partial access to. This is for an artwork storage company. We have about 40 clients and would like each to have access to their ...
3
votes
2answers
183 views

Designing a system to archive databases with referential integrity

I have a very large Oracle database, with many many tables and millions of rows. I need to delete some of the rows end-to-end. By end-to-end, I mean, if I want to delete a row from a table then I must ...
23
votes
6answers
7k views

How much business logic should the database implement?

I've worked in some projects where most of the business logic was implemented on the database (mostly through stored procedures). On the other side, I've heard from some fellow programmers that this ...
4
votes
3answers
2k views

Is the ADO.net Entity Framework appropriate when all you do is insert records in bulk?

My department develops software to migrate databases for our customers from their old CRM software to ours. In this process we could be inserting up do millions of rows, processed one at a time as we ...
0
votes
1answer
61 views

How can I iterate over two loops of mismatched sizes, keeping them in sync?

I have a database table in which each row is one movie (with fields like 'title', 'director' and 'writer'), and a related table where each row is one screenshot from a movie (with the fields ...
3
votes
0answers
100 views

Why there is a drop of interest in DBMSs? [closed]

I was playing around with google trends explorer when I tried to compare three major DBMSs: MySQL, Oracle and MS SQL Server. As you can see there is a drop in the interest in these database ...
2
votes
2answers
224 views

architecture of database heavy application

A program I'm currently designing is extremely database heavy, almost anything the user does will alter the database, or read from it. Now I have one interface which defines all these operations, and ...
2
votes
1answer
129 views

Multiple websites and applications using one user database

I've got several applications and websites that will be built around one main application. In a perfect situation users will be able to register once and be able to log into the different applications ...
4
votes
4answers
361 views

How to prevent race conditions in a web application?

Consider an e-commerce site, where Alice and Bob are both editing the product listings. Alice is improving descriptions, while Bob is updating prices. They start editing the Acme Wonder Widget at the ...
4
votes
3answers
135 views

How to track temporal changes in a database?

Imagine a software for theater owners. You can accept reservations for the different cinema halls. Each hall has a different number of seats. Say the owner wants to know how many people visited the ...
2
votes
1answer
87 views

Managing Database version controlled migrations using a list/table

I'm not much of an expert in the area but I am aware that solutions already exist to managing database migrations in version control, e.g. sqitch and liquibase. However I'm currently planning a small ...
4
votes
4answers
462 views

Organise C++ classes around SQL database

My question is about how best to organize C++ classes around a database model, and I understand this may appear very elementary. The software I propose to create will do the following. It is intended ...
3
votes
2answers
233 views

Why Do B+ Trees Have a Minimum Occupancy of 50%?

As far as I can tell, the basic operations (add, delete, search) on a B+ Tree would function the same if minimum occupancy was 1, or 1/3, or any other function on node size. All the sources available ...
0
votes
1answer
217 views

calculating the average of a value over a month [closed]

I am working on a project right now that is having me calculate monthly interest on a bank account. The way the interest is supposed to be calculated is as follows: Use the daily average to calculate ...
1
vote
0answers
159 views

Properly design program database to reflect organization structure

I'm having trouble setting up my program's database the 'right' way. I was hoping you guys could give me suggestions on doing it properly. I am creating a database+client for a non-profit organization ...
2
votes
0answers
150 views

Entity Framework Lookup Tables

I am coming from working with ADO.net DataSets and feel fairly comfortable with how they work. Mainly, I usually have a DATA table with a large number of REF tables for lookups. In DataSets it was ...
2
votes
2answers
51 views

Bulk update in client-server application

Sometimes when coding a client-server application, the client needs to make a bulk update. For example: "mark all pending orders as dispatched". To implement these I typically write specific ...
1
vote
0answers
106 views

Syncing structured data and files in Android App with an ORM?

I am developing an Android App which I have developed for iOS before. The app requires that structured data and files are synced across android devices. In iOS, I was using Core Data and synced to ...
1
vote
0answers
13 views

compare different approachs for saving related records whose values may change

On a web application for accounting services, I have the good old Invoice. To keep this example as simple as possible, each Invoice has many rows, and each row has its item with its price. At the ...
1
vote
0answers
64 views

Automatically verifying INSERTs when building a PHP(5.3.3) application

I am building a form in PHP. I would like to automatically verify that INSERT queries are successful, and populate data correctly, as opposed to running queries in Workbench or MySQL with every code ...
2
votes
2answers
137 views

Combine union with distinct

Situation: I need distinct results from two tables, that both have duplicates. I would like to know if I should combine UNION and DISTINCT. Example 1 - Only use distinct SELECT DistinctValue FROM ...
2
votes
3answers
236 views

What are the advantages/disadvantages of creating a new set of tables for each user?

I'm working/playing on an app where individual users' data will be completely independent from each other. Of course, there will be common tables for other parts of the app (e.g. "users"), but for the ...
0
votes
0answers
95 views

When to use a message queue as a web service database?

Does it make sense to implement a message queue system such as RabbitMQ or Kafka for the purpose of storing data in a queue? For example, this could be done in order to handle things such as ...
2
votes
3answers
678 views

What is a Database Environment?

I am going through Relational Database Design by JLM. I have come across words like database, data model, DBMS etc. which I am able to understand. But, I get confused when the author tries to use ...
6
votes
4answers
431 views

Heterogeneous Associations - Data Modeling When an Object that Must Relate to One of Many Classes

Suppose you have 3 classes: ClassA, ClassB and ClassC. Now suppose you have a class Message. You want a one-to-many relationship between each one of those three classes and the Message. The goal is ...
1
vote
1answer
49 views

Reduce Operations on Distributed Databases

I would like to ask you about optimizing reduce operations (e.g. count) on multiple databases. Let's say there is a user table that is stored in various countries and sharding is made based on the ...
13
votes
3answers
2k views

Database schema for a ToDo list

I am trying to make a very simple todo list application with PHP, MySQL, Jquery templating and JSON... However, my schema seems to complicate things in JSON. What's the best way to do it? A new ...
3
votes
1answer
110 views

Fixing bad data in a database - redo or incremental

I have pseudo-ownership of a fairly old db (original data from 30 years ago; current design is >15 years old). In my opinion, the schema is pretty broken, and one of the implications of this is that ...
0
votes
2answers
150 views

SaaS model, 1DB per client

The context we're building a web-based system and one of the design decisions (database related) was whether to have 1 main DB manage all client data VS having 1 DB per client. After reading a lot ...
1
vote
3answers
413 views

Database design: 4 types of users but have different functionality , separate or one table?

I have 4 types of users: Admins , normal user , company , service provider admins and normal user share some attributes (id .first name ,last name ,phone ,mail) company and service provider share ...
2
votes
5answers
97 views

Using DDL commands in programming language [duplicate]

Hello I am a student with no industry experience. My question may sound dumb, but, me and my friends were having discussions on use of DDL directly in programming language (any language may be Java, ...
1
vote
1answer
69 views

How to associate both a collection and one item of this collection to an entity

I'm working on a project in which I have an entity, we may call Users and another entity Address. I want to define the entity User in a way that an user would have a collection of addresses ...
16
votes
7answers
1k views

Does it make sense to standardize including a created date and last updated date field on all DB tables?

My boss is currently attempting to apply some development standards to our team, so we had a meeting yesterday to discuss the standards which was mostly going well until she brought up: All DB ...
1
vote
1answer
177 views

What is the point behind building an abstraction layer PDO Adapter class instead of using native PDO?

I have built a PDO adapter class because I thought, at the time anyway, it would be a good idea. After fighting with it, it makes no sense to me. Isn't the design of PDO the way it is to keep you ...
1
vote
1answer
135 views

Transferring information between a web server and a Python backend?

I have been Googling my problem but haven't been able to come up with anything; here's the situation: I have a PHP / MySQL website hosted with 1and1.com. I also have a Python program that runs on a ...