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

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1
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1answer
210 views

Is this database design good? What JPA Entities should I create for this design?

I am trying my hands on JPA. For this I am thinking of using the example of a student admission process as shown in the diagram below. Is this design good ? Any suggestions for improvement are ...
2
votes
1answer
258 views

How should I handle database failures in a web application? [duplicate]

I'm developing a simple RESTful API using Go's Goji framework (although this question is language-agnostic), in which parameters from the URL are queried against a PostgreSQL database. Here's how it ...
2
votes
1answer
131 views

Entity Framework Code First Centralized database deployment

I originally posted this on stack overflow but was told that here is a better place to ask this kinda stuff. I couldn't find any other similar answered question but if there is one please give me a ...
-2
votes
0answers
21 views

Python pandas and matplotlib or MySQL? [on hold]

Pandas is a great Python library that provides easy-to-use data structures and data analysis tools. I have been using it to aggregate, and analyze daily weather observation data which I get from an ...
51
votes
8answers
28k views

When would someone use MongoDB (or similar) over a Relational DBMS?

Im a bit confused......the whole NoSQL and such. When would you choose to use something like MongoDB over something like Oracle or MYSQL? I dont really understand....the "difference" as far as usage ...
0
votes
1answer
38 views

Recurring database migration

I'm importing data from older website to new one using database migrations. I have created first as one of first steps of development phase of new site. Then I planned to create another one, that will ...
0
votes
0answers
51 views

Abstracting the data in a relational database. [duplicate]

While working with data, which is in a relational database I came up with this issue. At first, I was just writing helper functions to retrieve A SPECIFIC data I needed for the current problem but it ...
0
votes
2answers
108 views

Getting to know my way around a database with hundreds of tables [duplicate]

I'm new to a small company that's pretty much run by one guy. He knows all the ins and outs of the system which is quite large. We have a database with about 300 different tables. I'm struggling to ...
0
votes
1answer
45 views

Looking for a good database of cities for website [on hold]

I am not a programmer however I will forward this to my programmer friend. I am asking on behalf of him. I am developing a website and I would like that website to have pages for every city in the ...
4
votes
3answers
130 views

Algorithm that generates a group of men and women who are each interested in everyone from the other gender

In my dating app, I need to compile lists of men and women where all of the men in the list are potentially interested in all of the women in the list, and vice versa. That is, in a list of 10 men ...
1
vote
1answer
52 views

How to minimize database deadlocks in a load balanced web application?

I'm working on a web application hosted on multiple load-balanced web front ends (WFEs). This application has an API method that performs a database query and returns the results. This query only ...
0
votes
1answer
22 views

Tags DB structure - tags table using one join and GROUP BY, or pivot (join) table using two joins?

I'm implementing tags into my question and answer application. Users will be limited to the tags available by the app, so they can't choose their own. So maybe only 30-50 tags will be available. This ...
12
votes
5answers
1k views

How come the computer doesn't have to read the entire table when the column is indexed? [duplicate]

Let's say a table with two columns has 100 quadrillion records. And I want to find a record that has column #2 equal something. If column #2 is indexed it returns the result immediately, but if it's ...
0
votes
2answers
100 views

Definition of the NHibernate Mapping by Code / EF Code First pattern?

Sub-questions: Does this pattern have a formal definition? Who invented it? Is it considered a DSL? The reason why I am asking is because I would like to better assess its applicability to ...
0
votes
0answers
59 views

What is the design pattern name for a class that handles 2nd level caching? [duplicate]

I have a system where I want to start introducing some 2nd level caching. I want to abstract data access a bit and allow some type of other class to do the dirty work of fetching a DTO; it will check ...
15
votes
3answers
7k views

Is there a list of common usernames to reserve in a new system?

I need to reserve usernames in my new website. These generally fall into three categories 1) usernames no-one should have (eg: admin, user, service, help, root, etc) 2) names of super famous people ...
-1
votes
0answers
48 views

Best way to store large geo-tagged data? [closed]

I am developing a web-app which will run on Google app-engine(GAE). I need to store a reasonably large (few million entries) dataset, with each entry consisting of a data-point descriptor, a lat-long ...
-3
votes
0answers
54 views

Live cases of using DB queries with over 20 JOIN relations [closed]

Why would one use queries with 20 or more (maybe even 100+) JOIN relations? What are some open source systems from different fields making use of such queries? It would be interesting to look at such ...
0
votes
0answers
21 views

Planning complex Mongo (And possibly other NoSQL) Databases

There is no "right way" to do anything, but there are "better" and "worse" ways, as well as true and tested ways. I'm studying Mongo and considering it for a project. It's gonna start small but ...
-2
votes
0answers
47 views

Simple way to write to SQL file from Java [closed]

I am creating an application to write to a .db SQL file that will be sent to a client and read from.I have seen many tutorials on SQL databases but what I needed was more in the realm of embedded ...
24
votes
8answers
5k views

Front end first or Back end first. Of the two which is a Good system design pratice?

I have a client right now requiring me to develop a school enrollment system. Now this is the first time im having this kind of challenge. Most of the past software that i created are not that ...
1
vote
0answers
47 views

How to off load DB & API calls (PHP Heroku App) [on hold]

I took over support for a PHP app that runs on Heroku. After analyzing the performance with New Relic, I'm noticing that the three bottles necks are the database and API calls to outside services. ...
2
votes
1answer
83 views

Strategies for handling or avoiding race conditions

I'm working on a .NET application where I off-load my DB work (save operations) to a separate thread (inspired by how NodeJS handles IO operations). A save operation comes down to this (using Entity ...
6
votes
7answers
256 views

How would you design a user database with custom fields

This question is around how should I design a database, it can be relational / nosql databases, depending on what will be the better solution Given a requirement where you'll need to create a ...
5
votes
4answers
234 views

Two Database Architecture : Operational and Historical

I thought about an uncommon database structure and wonder if anyone has seen it in use before. It's basically using 2 databases: First database hold only the data that is currently valid Second ...
0
votes
1answer
154 views

Dealing with several custom getters

I have a data structure with data units containing different types of data. I've wrapped the data in "Field" objects so that each field is able to independently parse user input in a desired way. ...
0
votes
0answers
21 views

Hybrid Apps and Storage - how does it work with Native apps and which to use?

I'm using Ionic at the moment. I believe, like many others, that hybrid apps will become more more common/important than they are now simply because the frameworks are getting better and better. ...
2
votes
3answers
64 views

How to save many changes to database data?

I'm working on a feature which will pull many (say, 1000-5000) rows from a database, display them to the user and allow the user to edit them. This editing may involve changing text; adding rows at ...
0
votes
0answers
31 views

How can I model this scenario in a graph database?

I'm developing an application where users can tag resources and it's also important to know who tagged the resource with a specific tag. A graph database seems like a good fit for this and the rest ...
4
votes
1answer
206 views

How does the team ensure a good DB design? [closed]

We want to ensure that our team delivers a good performing DB design. But we are not quite sure how to achieve this. Couple of solutions have been suggested within the team: Adding DB indexes to ...
1
vote
1answer
53 views

Proper tree NoSQL structure with focus on full-text searching

I developing an app with tree(folder-file) structure, on which I should perform full-text searches with MongoDB. I did a research on the best tree structure practices and found this great article, but ...
0
votes
1answer
61 views

Like structure table with Laravel and showing the most popular content at top

I am using Laravel to creating a website, my users can post questions and other users can write their comments under the post, each comment have Up vote and Down vote, and users can voting for ...
-2
votes
0answers
12 views

Database solution for multi-user uml-ish application [migrated]

I'm working on a Eclipse RCP-based application that will switch from single user local storage to multi-user database storage and are now considering what storage solution to use. It's sort of UML ...
2
votes
2answers
198 views

Creating a separate table for images or adding “image fields” to many tables?

I need to create a database in which several tables have images. For example, users have profile pictures and uploaded ones and products have many pictures, as well. Is it better to have one MySql ...
0
votes
1answer
115 views

Where should the following business logic be written?

I have a C# console application. This application has many different projects/C# class files, each of them dedicated to parsing a certain kind of XML and creating an object, called 'Response'. Now, ...
1
vote
3answers
181 views

OOP implementation doubts with databases

I was starting a project today and after designing the database structure and how the data would be stored etc, I started the implementation. I am doing this on php, but the language isn't really ...
0
votes
0answers
46 views

SQL: GROUP BY where a column is unique [migrated]

So I have this one giant table e.g. PROD_IDGEOG_IDTIME_IDVALUE1 1      MT     JAN    100    ...
58
votes
10answers
6k views

Is it premature optimization to add database indices?

A colleague of mine today suggested that we go through all of the queries in our application and to add indices accordingly. I feel this is premature optimisation because our application is not even ...
3
votes
2answers
115 views

Design, how to utilize The Hardware (multiple threads and/or GPU) while indexing (via a database) a very large set of binary files

Problem How can design my file parser to maximize the hardware when processing (creating meta data for) a large file (i.e. how to avoid being blocked by IO and running out of memory) preferably ...
2
votes
2answers
159 views

Communication/Updates between units of works/entity framework contexts, colliding with user changes

I'm developing a WPF application using Entity Framework for my database communication. The application has a hierarchy of tabs where each tab has a db context. Each tab allows the user to view some ...
1
vote
2answers
152 views

Best approach for a server configuration data collection and reporting solution from a legacy script?

I have a project which involves collecting config data from windows servers in our (very large) server estate. My manager wants me to collect over 150 data items across all configuration areas ...
0
votes
1answer
43 views

REST and foreign key constraints

I have a rather complex database schema using foreign key constraints. This database schema will be accessed with REST services. Should REST or the database be responsible for referential integrity? ...
3
votes
2answers
243 views

implementing dynamic query handler on historical data

EDIT : Refined question to focus on the core issue Context: I have historical data about property (house) sales collected from various sources in a centralized/cloud data source (assume info ...
0
votes
0answers
11 views

How to use an Address Gazatteer in an application that contains addresses

Say I had access to the post office address file (http://en.wikipedia.org/wiki/Postcode_Address_File) and wanted to cleanse about one million addresses. I am trying to think of an "algorithm" to do ...
4
votes
1answer
70 views

Should I implement the consumer/producer pattern in my java video app, and if yes, how?

I built a small video frame analysis app with desktop Java 8. On each frame, I extract data (5 doubles now, but could expand to a 1920x1080x3 OpenCV Mat in the future). I would like to store this data ...
1
vote
1answer
345 views

Creating a online database creator

I've been thinking of creating an online database creator (think DabbleDB, Zoho Creator, Intuit Quickbase, etc.). I've been thinking of a couple solutions: Have 4 database tables: Tables, Rows, ...
2
votes
2answers
375 views

Separation of retrieving data and business objects between DAL and BLL Layers

I did some research before posting this question. Among other questions or post, one of those is provided below. I could not get a clear mind how to determine.. Business Objects within a Data Access ...
0
votes
3answers
208 views

SOA, Java EE and data organization

At the company I work for, we're currently splitting up our monolith solution into a number of small services (SOA). The purpose of this is to make the developers working on each chunk of code ...
2
votes
1answer
90 views

Which approach would be better for persisting these overridable configuration keys and values? A simple key-value store, or a graph database?

I'm creating a system where there are config keys and values. So for example: config.key = 10 Is an example of a configuration key and a value. These keys can also have overrides based on ...
1
vote
1answer
67 views

how to decide when to use database replication vs. custom REST applications vs. message brokers (pub / sub)

We have a distributed solution that's currently under design. There are a few points of integration where some application needs data from someone else and vice versa. We could solve by either ...