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

learn more… | top users | synonyms (1)

-3
votes
0answers
19 views

On Demannd PostgreSql 1:M Database Synchronsation for Selected Tables

Requirement is like I need to perform database sync on Demand or Event base for Selected tables of Admin Database to Client Databases. So I need an any open source php tool or library that will ...
0
votes
1answer
31 views

Should data be stored to local database in Android when heavily using REST services?

Let's say I have an application that has constantly changing data. Changes are so frequent that you basically need to refresh data every time you open some screen and keep refreshing it. Is it worth ...
3
votes
1answer
111 views

End user query syntax?

I'm making a command line tool that allows end users to query a statically-schemed database; however, I want users to be able to specify boolean matchers in their query (effectively things like "get ...
2
votes
4answers
80 views

In a large statically-typed software project with non-dynamic manual sql statements inside of it, how do you verify all the sql syntax?

One of the things I seem to struggle with frequently is the need to deploy a software application to test the database interaction. More often than I'd like, I have a syntax error or typo in my sql ...
3
votes
2answers
59 views

An algorithm for finding subset matching criteria?

I recently came up with a problem which I would like to share some thoughts about with someone on this forum. This relates to finding a subset. In reality it is more complicated, but I tried to ...
-2
votes
0answers
33 views

Webapp that shows a table

I have a C# web app that shows a database table on a webpage. I am not convinced that I'm doing this the best way and am looking for people's opinion on a better way to do this. Here's what I do so ...
7
votes
2answers
2k views

Data Synchronization in mobile apps - multiple devices, multiple users

I'm looking into building my first mobile app. One of the core features of the application is that multiple devices/users will have access to the same data -- and all of them will have CRUD rights. I ...
0
votes
0answers
28 views

n:m as the only way to store notifications?

I have a user and a notifications table. I want to make sure that every users sees a new notification once and only once. Not more, not less. The intuitive idea is to have a n:m relation table with ...
0
votes
3answers
132 views

What constitutes a good Database System(Java / SQL related) [on hold]

I've given this so much research but still couldn't come to my own conclusion, before continuing this question I would like to give you a rough idea of my current situation. I'm 18 years old and have ...
2
votes
3answers
100 views

Multiple many to many relations or one option table?

Let's say I have a database of persons who have some properties. For the sake of this problem let's say all of these properties relate as N-N. I can either create two tables for each property (one ...
2
votes
0answers
31 views

How do tablespaces differ in DB2 from databases in MySQL or MS SQL Server?

In DB2, it seems there is a strong separation between what a database is and what a tablespace is. Where as in MySQL and MS SQL Server tablespace and database seemed to be used synonymously. What ...
0
votes
2answers
48 views

Static and dynamic data : should I use different databases?

Say I am building a website that uses two different types of data : Static : information that will hardly change, like movie awards or world countries names (I want fast access so no external API) ...
-2
votes
0answers
21 views

Google App Engine File Upload Error - PHP [closed]

PHP Warning: File Upload Mime headers garbled in Unknown on line 0 When i am trying to submit form with large data in texarea and uploading image also.
12
votes
3answers
1k 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. ...
0
votes
1answer
57 views

Best way to deploy database-dependant application

I have always "custom developed" software for clients. This means: Develop the software Install SQL Express on client site Import DB, create DB user, set DB permissions etc. Install software on ...
3
votes
5answers
232 views

Is it useful to keep 'definition' entities in a database vs using an enum?

In a project that I have started working on, the database has a lot of FooDefinition tables which act like an enum. It's a C# project using Entity Framework although that is not central to the ...
-2
votes
0answers
28 views

JTree is Only Visible Part of the Time [migrated]

I am trying to populate a JTree from a SQLite data base. When it does show up, the JTree is populated correctly, but is only shows up about half the time. Why would it do this? public class ItemPane ...
2
votes
2answers
704 views

Database model for keeping track of likes/shares/comments on blog posts over time

My goal is to keep track of the popular posts on different blog sites based on social network activity at any given time. The goal is not to simply get the most popular now, but instead find posts ...
0
votes
2answers
166 views

Google App Engine overview

I have gone through many Google App Engine tutorials, and I became quite familiar with how to do basic stuff like implementing a webapp2.RequestHandler, and using ndb.Models to manage your data. Now, ...
3
votes
1answer
52 views

optimize human-readable database with index

i need to store a large amount of data - about 10 million entries of the format unique hash (64 chars), value 1 (5 chars), value 2 (9 chars) i will be reading and deleting (but not updating) this ...
3
votes
1answer
122 views

Good way to handle the notification counter like Facebook does

I want to build a similar notification mechanism that Facebook handles. I actually store the user's notification in an SQL table (actually it's a graph database but everybody master RDBMS terms). ...
0
votes
1answer
49 views

Multiple intranet/internet systems partially working on same data - database strategy

We are starting rewritting our apps (Internet portal, millions of unique users and few CRM/ERP systems, few hundred users) and we have a huge decision to make now. We are going to write them mostly ...
1
vote
4answers
144 views

MySQL Database design - Opinions

Im working on a web Application for our bussiness with my brother. Our application its pretty simple, will be develop with php and mysql. Clients and providers ABMs Articles Inventory (we do not ...
0
votes
1answer
131 views

Keep user and user profile in different tables?

I have seen in a couple of projects that developers prefer to keep essential user info in one table (email/login, password hash, screen name) and rest of the non essential user profile in another ...
2
votes
1answer
106 views

How to model a one-mandatory-of-many relationship

I have following class model that I'm quite happy with: A Whole has a special mandatory Part. Furthermore it has a collection of parts, that contains at least the mandatory part, but may contain ...
1
vote
2answers
252 views

How to update a row in database without ID?

I've got a table with the following structure : Col1 | Col2 | Col3 A | B | C A | C | B E | D | C The primary key is (Col1,Col2,Col3). I get the data in another project and ...
3
votes
2answers
137 views

How are composite tables generally handled when there is no ORM tool available?

I am developing a Windows Runtime Component (C#) to be used in an HTML/JS frontend for a Windows Store App. Now, one of the requests is to have a database on the local system to store metadata about ...
0
votes
1answer
278 views

PHP class data implementation

I'm studying OOP PHP and have watched two tutorials that implement user login\registration system as an example. But implementation varies. Which way will be more correct one to work with data such as ...
1
vote
2answers
94 views

Databases and the single responsibility principle

Can the single responsibility principle be applied to databases? relational databases I mean. I'm asking this because a typical database will have several tables and we may find something like that ...
6
votes
2answers
236 views

How does datomic handle “corrections”?

tl;dr Rich Hickey describes datomic as a system which implicitly deals with timestamps associated with data storage from my experience, data is often imperfectly stored in systems, and on many ...
0
votes
1answer
70 views

Locking database records

What I have right now: A table with lot of records. About 200 users can select a record according to some rules based on the data in each record. There is a high chance that 2 or more users will ...
1
vote
1answer
229 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 ...
3
votes
1answer
157 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 ...
1
vote
3answers
102 views

Let applications share a database or keep them in sync with web services?

We have decided to build separate applications for user authentication and user management. The reason is that the the former is a "this just needs to always work, and do so instantly" style service, ...
0
votes
2answers
148 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 ...
12
votes
7answers
1k views

Why shouldn't you develop on production database? [duplicate]

I need help with organizing my arguments for why it's MADNESS to develop against production data. Backstory: I started working here six months ago and I noticed we're developing directly against ...
2
votes
2answers
94 views

Should I be using a composite key for this table?

My database is going to store words, so the Word table is the most important. The Rhyme table lists which words a particular word perfectly rhymes with. It consists of three fields: RhymeID - primary ...
0
votes
1answer
50 views

Should I persist notification before or after publishing it through Redis pub/sub?

I'm implementing a mechanism to notify a group of users about newly inserted blog comments. The architecture uses the Redis Pub/Sub mechanism. By definition, the pub/sub mechanism aims to propagate ...
0
votes
0answers
38 views

Connection Pooling

As an example, I am using PostgreSQL with an application-layer connection pool, such a a JDBC connection pool. The specific JDBC connection pool is not important. My question is more about the actual ...
0
votes
0answers
29 views

How to test for performance or locking issues of sharing a database with another app

I have a typical Spring/Hibernate Tomcat webapp that has a user_info table. I’m trying to create another webapp that will do CRUD actions on the user_info table. I'm considering sharing the same ...
0
votes
0answers
47 views

Save database changes in service layer or controller mvc .net

I have recently been using a service layer to abstract away alot of the business logic of my application. However I've come into an issue where I'm not sure what is best practice on doing the actual ...
11
votes
4answers
308 views

Database design - Store state or compute state every time?

Let's say I have a relational database application and a "user" object and a "message" object. Now I want to show the number of unread messages to this user. What's the best way to archive this? Do I ...
14
votes
2answers
10k views

Creating database connections - Do it once or for each query?

At the moment I create a database connection when my web page is first loaded. I then process the page and run any queries against that conection. Is this the best way to do it or should I be creating ...
0
votes
2answers
154 views

Examples of designing a database that handles point tracking?

I'm attempting to expand my knowledge of how database designs and concepts work. I'm working on a hobby web/mobile app for practice that will challenge me. However, I am running into an issue. What ...
4
votes
5answers
1k views

Structuring database for multi-object “activity” and “following” functionalities

I am working on a web application which operate with different types of objects such as user, profiles, pages etc. All objects have unique object_id. When objects interact it may produce "activity", ...
2
votes
1answer
334 views

Which is the best method for storing data for a Language Dictionary?

I have been working on making a completely offline dictionary using the Wiktionary XML dumps. The dumps themselves are about 10 MB, but when converted into a index using a search engine indexer (I use ...
0
votes
2answers
89 views

Guidance on connecting a common database to several instances of the same application [closed]

I'm looking for advice regarding a future development of mine, concerning a application that may be run in several machines that need to use and manipulate the same data. As this sounds somewhat vague ...
3
votes
4answers
367 views

Best practices when creating/modeling databases?

I learned at the University some steps to model a database: Model the problem using the Extended Entity-Relationship Model. Extract the functional dependencies Apply some algorithms to normalize ...
0
votes
0answers
139 views

Extending user registration in Django site that uses both site admin tables and my own module?

I'm writing a Django site that registers a particular type of user and this is done by the resources that come with the framework, the site administration. The issue: I'd like to create a new model ...
0
votes
0answers
26 views

What are the memory-management capabilities of MySQL + JDBC (in light of autonomic computing)?

I'm interested in implementing some kind of autonomic-computing functionality using MySQL. By autonomic-computing I mean roughly some failsafe abilities, whereby the application appears to be at least ...