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

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0
votes
1answer
60 views

Three-Phase Commit (3PC) question

I've been reading about 3PC in a text book, but there aren't any diagrams or examples, so I found one on wikipedia that I posted below. My question is, what does it mean by "cohorts?" There is no ...
1
vote
0answers
48 views

Three phase commit protocol

I'm trying to understand the three phase commit protocol by reading the wiki page (http://en.wikipedia.org/wiki/Three-phase_commit_protocol#Motivation). In the description for the diagram I posted ...
-1
votes
0answers
22 views

Polyglot database architecture [on hold]

I'm currently working on my first data-centric app, and I'm wondering what the most efficient architecture is. I am wanting multiple databases; Mongo, SQL, Titan, Cassandra, and ElasticSearch. I am ...
-4
votes
0answers
28 views

Mediation Transition [on hold]

What is Mediation Transition and Data Intregration in terms of Database ? I do understand the ETL which says Extract, Transform and Load which is migration. I have a hard time figuring out the ...
-5
votes
0answers
29 views

Project help and advice? [closed]

I am looking for advice and help if you kindly could. I need to find a ggod set up for my project. I am working on a project. I am at beginner level in python !! I want to learn Python and refine my ...
-1
votes
1answer
68 views

SQLDatabase: Read a lot of data at once and process in memory or read the data when I need it?

I'm not sure how to approach this problem. I require a big chunk of data records from the SQL server. This chunk is based on variables, so I don't know before what records I need. I need to do a large ...
-2
votes
0answers
52 views

Architecture for “Friend of a friend 'likes' feature” [closed]

I read a few of existing posts like facebook calculate, fb db design and also some of the neo4j notes, also the pit falls of going with mongo for diaspora. I signed up into one of the diaspora pods. ...
0
votes
0answers
18 views

searching for a user's friends

I have a rails that uses sunspot/solr for searching a number of models in our app. We are now adding a feature for searching for a user's friends. So if I look for "joe" all of my friends named ...
1
vote
1answer
31 views

What should the payload of a “domain event” generated through “change data capture” include?

Using domain driven design and event sourcing ... Given I have a table of 3 columns: (A, B, C) with an existing row of data: (1, 2, 3), when I update the row to contain values (1000, 2, 3) and I run ...
0
votes
1answer
39 views

OpenLDAP as tree database [closed]

I have some data which is hierarchical in nature (actually a forest) and rather big in size, although not enormous, in the order of tens of GB, or billions of nodes. This data is not going to change, ...
12
votes
8answers
648 views

When does one hard-code actual data values into the code as opposed to using a DB?

A long-standing question for me has been: when do I store data (actual values) in a database table, and when do I store them right in the code? The untold consensus (*) has typically been as such: ...
0
votes
3answers
87 views

Website testable design [duplicate]

I have developed two web services. The main service is a RESTful service (using DB), and another UI service that uses the RESTful service. Say I want to test the UI for now (integration tests), every ...
1
vote
1answer
82 views

Database choice [closed]

I am working on a system where I am replacing and existing Cobol system with C#. For the database I have hit some requirement which I am having a hard time to find complete support for (tried SQLite ...
1
vote
1answer
85 views

Representing list of polymophic objects in db

Let's suppose I have a list of derived objects from some base: class Circle : public Shape; class Rectangle : public Shape; There is object, which has vector of Shape * as member variable: class ...
2
votes
3answers
183 views

Is there a 'standard' SQL that can replace all the various custom versions?

I have been writing SQL for over 10 years now. I am extremely proficient at it and have experience working in SQL Server, Oracle, MySQL, PostgreSQL, etc. While there are multiple standards out there, ...
0
votes
0answers
27 views

How can I aggregate data from separated databases in more efficient way?

Firstm I'm using PostgreSQL 9.3. I'm solving the problem which is to retrieve a data from a separated databases and to render it into a web page. The web project is on the Java (JSF 1.2). Presently ...
-3
votes
1answer
94 views

How can I test a method which aggregates data from a database? [closed]

I'm developing the web Java application and come across the following issue: I'm using jUnit 4.5. Suppose that I have a method which aggregates data from a database for the rendering their to a ...
1
vote
2answers
102 views

When should I implement authentication in a database?

I'm currently embarking on a MongoDB project (a simple user login system), and I notice that there is an option for authentication. Here is the server string, with the userinfo shown as optional ...
2
votes
1answer
81 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 ...
15
votes
4answers
3k views

Databases: Where should the application logic run? [duplicate]

http://highscalability.com/blog/2010/11/9/facebook-uses-non-stored-procedures-to-update-social-graphs.html talks about how Facebook moved logic out of the database into the application in order to ...
0
votes
1answer
42 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 ...
0
votes
2answers
58 views

Are the concept of database driven website and the CMS made website same?

I'm having little difficult time of understanding the few logics of web development. Should I call home page, about page (or any other pages of a website whose contents change very rarely and no ...
0
votes
6answers
115 views

Should I rebuild my read only database every time I launch my server?

I'm getting into web development, and I'm trying to get a grip on databases. In an app I want to make, there is a read only database that will be filled up with a large amount of data, which will be ...
0
votes
1answer
94 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 ...
0
votes
0answers
95 views

Evaluating local storage for data persistence for small, stand-alone applications

TL;DR - I have a standalone application that will remain relatively small. I'm trying to evaluate between using XML files or a lightweight database for local storage of data that needs to be ...
0
votes
1answer
44 views

How to implement a Daily Recap email of Database records modified the previous day sent to Subscribed Users like Basecamp does?

I am building a Project Management module for SugarCRM. It consists of a "Project" which has information on the project like Name, description, start and completion dates, creator name, status ...
4
votes
3answers
319 views

database design, how to handle freelancers

The context i'm modeling a database for a small ERP system. However I've recently hit a difficult spot that I'm having a hard time wrapping my head around. The logic of it involves a few special ...
1
vote
1answer
120 views

Are CRUD operations intended to be used with collections?

CRUD operations, by definition are... interfaces that permit users to create, remove, modify or retrieve data Implementations of CRUD interfaces can come in various shapes and sometimes they are ...
0
votes
1answer
57 views

Real time middleware system: Direct DB access vs REST API access

I'm developing a complex environment which involves a web application, a mobile app and a real time middleware system which accesses the DB for on-site tag readings. Currently, the web application ...
0
votes
2answers
87 views

Is a mocking framework useful if I'm unit testing a repository/database? [duplicate]

I'm trying to improve my testing skills. I frequently hear about mocking framework to build fake objects (as far as I understand). Right now I need to test my repository (the usual add, remove, update ...
3
votes
2answers
134 views

Is a bad practice create database structure on the runtime?

Im creating a crawler app that will always in the beggining, when the Class constructor, ensure that the basic database structure exists. Is this a bad practice? What is the advantage os creating the ...
2
votes
2answers
77 views

Unit test database insert/remove and atomicity

I create my compact test database. This is a SDF file, embedded as a visual studio resource. When test suite starts this database is copied in %LOCALAPPDATA% so my test can use it. The first method ...
0
votes
1answer
81 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 ...
0
votes
0answers
26 views

Storing last polled database timestamp unix

I have a Unix script which is called by a scheduler (CTRL M) every 3 seconds. The script queries an external database(not belonging to my application and therefore I can only query it) to check for ...
0
votes
1answer
107 views

Are there two type of associations between objects or are there just different representations?

I've been spending some time on 're-tuning' some of my OOP understanding, and I've come up against a concept that is confusing me. Lets say I have two objects. A user object and an account object. ...
1
vote
1answer
94 views

Automatic denormalization for a NoSQL database application

We have a use case where we store table-like data, but we know about the schema of the data only at runtime. In our application, a power user defines a schema and normal user can create records and ...
6
votes
3answers
271 views

Proper Response to HTTP Request When Too Much Data is Requested

I'm building an API for an ad serving platform that will allow you to request tracker data for ad campaigns. Campaigns often exceed hundreds of millions of requests, which means there will be many ...
3
votes
7answers
223 views

Are mutliple database calls really significant with a network call for a web API?

At one of my employers, we worked on a REST (but it also applies to SOAP) API. The client, which is the application UI, would make calls over the web (LAN in typical production deployments) to the ...
2
votes
2answers
72 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
5answers
133 views

Database design with performance issue and use of views

I am designing database for a school system. I am having to create a lot of tables and a lot of link tables to maintain a structure in the system. I am trying to maintain foreign integrity and trying ...
1
vote
1answer
81 views

How to save appointments in database?

There are 2 entities. One is admin. The task of admin is to define slots for appointments which will be taken by applicants. The admin will choose a default time for the appointments like 10am to ...
3
votes
2answers
127 views

Whether to store all numbers or just their ranges in database for this application

I'm developing a (PHP MySQL) Web App which will sell dynamically generated real time cell phone numbers for cellular companies. A company will ask for, say, a thousand numbers and this app will check ...
0
votes
1answer
34 views

Tweaking a ranking algorithm from a few variables

I'm going to have a mySQL table with elements in it and would like to rank them in the same manner than Reddit but not quite. I'd like to know how to add or remove importance to a variable in my ...
0
votes
1answer
80 views

Efficiency of getters/setters with database performance

I'm currently in the process of refactoring a very old personal project of mine, which used procedural PHP-in-HTML code. I'm modernising it as a learning project, using OOP where beneficial. I ...
0
votes
0answers
45 views

Database conceptual Question [duplicate]

When querying in database through PHP, is it good to open mysql connection before every query and close it as the query completes? or should we open the mysql connection as soon as the first query ...
0
votes
2answers
150 views

Database Handler and SQL injection prevention

I've written a database model class in PHP and have written a controller class that specifically validates the data before sending it to db. I'm getting criticism that I should handle the data in ...
-1
votes
2answers
90 views

Loading database in memory vs querying

I am currently developing a continuous backup software. The key feature of the software is instant backup meaning that each time a file is created, modified, renamed or deleted the change is ...
2
votes
1answer
55 views

Using json as database with EF, how can I link EF and the json file during DbContext initialization?

For a personal testing-project I am considering to create a SPA with the following technologies: ASP.NET MVC + EF + WebAPI + AngularJS. The project will make use of small amount of data, so I was ...
0
votes
1answer
74 views

Prepared statement alternatives for this middle-man program?

I have an program that is using a prepared statement to connect and write to a database working nicely, and now need to create a middle-man program to insert between this program and the database. ...
2
votes
1answer
87 views

Finding a way to simplify complex queries on legacy application

I am working with an existing application built on Rails 3.1/MySql with much of the work taking place in a JavaScript interface, although the actual platforms are not tremendously relevant here, ...