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

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8
votes
2answers
3k views

Best method to implement a filtered search

I would like to ask you, your opinion when it comes to implement a filtered search form. Let's imagine the following case: 1 Big table with lots of columns It might be important to say that this SQL ...
5
votes
5answers
268 views

Database-stored configuration management

Developing database-backed software, often one finds it convenient to store stuff in the database which one might traditionally express in code, but which is useful to store in the database (so that ...
3
votes
1answer
129 views

Enterprise Wide Keys [closed]

I have for a long time been working on an ODS as well as Data Warehouse. Both are integrating a wide variety of data sources from stove pipe applications. One of the uses of the ODS is to provide ...
0
votes
4answers
3k views

Application connecting to database server

I'm working on an application which requires user credentials and so on. So a database is required on the backend. What is the best practice to connect to a database without hardcoding your password ...
1
vote
2answers
183 views

What is volume in terms of databases?

I was reading a text. It said, "Information presentation must be compatible with the response time needs of systems. The response time should be short enough that the information does not lose its ...
13
votes
8answers
5k views

Should we ever delete data in a database?

I am new to databases and trying to understand the basic concepts. I have learned how to delete data in a database. But one of my friends told me that you should never delete data in a database. ...
1
vote
1answer
102 views

Eager Loading Constraints

The thing is, eager loading some object with all of it's associations reduces the queries made to the database, but the query time is greatly increased. The question is: This increased query time in ...
11
votes
4answers
1k views

Data architecture for event log metrics?

My service has a large ongoing number of user events, and we would like to do things like "count occurrence of event type T since date D." We are trying to make two basic decisions: What to store? ...
0
votes
1answer
209 views

Keeping “historical” migrations in Django-south

After a system has gone through many migrations, and evolved enough for a second version, does it make sense to keep the old migrations around? I mean, old versions will use them to upgrade to the new ...
0
votes
1answer
343 views

RDBMS same type of optional data for multiple tables

I have an embedded database (SQLite), it stores information about events and page views, its purpose is to track the user journey inside my application. I need to provide support for optional custom ...
2
votes
2answers
1k views

Design pattern for access to tree-like database in Java?

I'm developing a Roleplaying character viewer/manager programme for a locap LARP system. The Characters have access to skills that are layed out in a tree-like structure. There are a lot of skills, ...
7
votes
1answer
796 views

Are there tools that do automated validation of database standards?

I'm looking for something akin to FxCop, but for databases. Basically, I want to have a tool where I configure my database standards (naming conventions, field types, or more complex custom rules). ...
5
votes
1answer
223 views

Why use binary files to stack up different versions on DMSs?

I've used both Liferay and Alfresco trying to use them as the Document Management System for an intranet. I noticed the following: They use the file system and the database to store files They use ...
6
votes
3answers
3k views

How should I encapsulate database access?

What are some examples of good class structures used to manage database access? I am a fan of class encapsulation and would prefer the containers (e.g. car) not to perform database tasks. I would ...
3
votes
1answer
2k views

Rails application - how to optimize/reduce database calls when iterating over a collection

What's the best way to optimize a Rails app where you need to pull info from the database for a collection of items? For example, if I am building an online forum system... I would have a number of ...
5
votes
6answers
3k views

Ways to have a history of changes of database entries

What are ways to allow the versioning of database entries (data)? Think of the content-managment-systems abilities to revert back changes of articles. What are their pros/cons?
13
votes
6answers
9k views

Is there any reason to use varchar over text columns in a database?

Is varchar just a remnant from before text came around, or are there use cases where you would want to use a varchar? (Or char for that matter..) (I use Postgres and MySQL (MyISAM) daily, so those ...
2
votes
3answers
2k views

Database ERD design: 2 types user in one table

I have read this (Database design: 3 types of users, separate or one table?) I decided to put admin and normal user in one table since the attributes are similar: fullname, address, phone, email, ...
2
votes
1answer
207 views

In-memory DB to perform intersects on set slices

I have a specific programming need where I need to efficiently store large sorted sets in memory, query them for ranges, and intersect them against other sets that are also queried for ranged. I am ...
2
votes
2answers
155 views

Developing an Interface to a Dynamic System

I work for a small company and have been designing a GUI to interface our embedded system. The problem with this embedded system is that it is not a finished product (may never be) and is constantly ...
0
votes
8answers
4k views

I need an approach to the problem of preventing inserting duplicate records into the database

A webservice that I call returns a list of data. The data from the webservice is updated periodically, so a call to the webservice done in one hour could return the same data as a call done in an ...
4
votes
1answer
497 views

How to get experience in large scale databases?

I have written applications that are very small scale and the code I write works fine for them. But I have often wondered how the server side code I write would scale up from 100s of queries per day ...
0
votes
2answers
177 views

How should I handle using two databases with a legacy PHP application?

I have a legacy PHP application that was written in 2004 and uses MSSQL as a database backend. At this stage MSSQL is still supported by PHP but only just via a Microsoft driver. I have looked at ...
1
vote
2answers
222 views

ORM has schema to generate classes, does the reverse exist? [closed]

In Entity-Framework, you can create a DB schema, and then generate your ORM classes. Is there any software that does this in reverse? For example you create a few classes that have relationships, ...
1
vote
2answers
736 views

Generate sequence of string of 4 characters

I'm facing problem with generating character sequence for SMS tracking. there should be a easy to enter code send with all the outgoing messages. Reply SMS will map with that code. I can't generate ...
5
votes
2answers
599 views

Amazon SOA: database as a Service

There is an interesting interview with Werner Vogels which is partly about how Amazon does Service Oriented Architecture: For us service orientation means encapsulating the data with the ...
1
vote
2answers
307 views

Designing a hierarchical structure with lots of reads and writes?

I am in the process of working on a video on demand system part of it involves the management of a hierarchical tree structure (think windows explorer) which allows users to upload videos, move ...
16
votes
7answers
703 views

De-facto standards for customer information record [closed]

I'm currently evaluating a potential new project that involves creating a DB for typical customer information (userid, pwd, first & last name, email, adress, telfnr ...). At this point, ...
3
votes
6answers
530 views

How to define a natural id in database?

There are a lot of manuals. I am trying to create an database to hold information of these documents. But, there is a small problem. How can I give meaningful id to the manuals? Are there any ...
15
votes
2answers
5k views

Conflict resolution for two-way sync

How do you manage two-way synchronization between a 'main' database server and many 'secondary' servers, in particular conflict resolution, assuming a connection is not always available? For example, ...
12
votes
5answers
887 views

For an ORM supporting data validation, should constraints be enforced in the database as well?

I have always applied constraints at the database level in addition to my (ActiveRecord) models. But I've been wondering if this is really required? A little background I recently had to unit test a ...
2
votes
3answers
314 views

Should each app have its own database, or should small apps be merged into one? [duplicate]

Possible Duplicate: Should I use one database per application or share a single database amongst multiple applications We have a bunch of small to medium sized apps, each of which has its ...
1
vote
2answers
349 views

Centrally managing 100+ websites without bankrupting a small company [closed]

I'm mainly interested in opinions on the trade-offs between having a single central server all the websites connect to as opposed to each website mirroring a subset of the master database with all the ...
10
votes
3answers
1k views

How do you put a database online? [closed]

I have a very beginner question regarding web development. I've had some experience with JSP, Hibernate, and MAMP to create a simple system for tracking inventory and sales. But this was all done ...
0
votes
2answers
538 views

Save match details to SQLite or XML? [duplicate]

Possible Duplicate: XML vs SQL for small projects? I'm making a (conceptual) system to simulate any kind of sports match (like soccer,basketball,etc) with actions (for example ...
0
votes
1answer
137 views

How to use database adapters' cursors safely?

I started to use psycopg2 to connect my little python script to a PostgreSQL database few days ago. After some research I found that a lot of database connector, like psycopg, work using cursors. I ...
0
votes
1answer
213 views

non-volatile virtual memory for C++ containers

Is there a virtual memory management process that would allow a program to use the standard container structures and classes, but retain these structures and their data when the program is not running ...
7
votes
2answers
511 views

What is the algorithm for expiring items in key-value storage?

I was thinking on how current key-value storages implement "expire date" for items. Currently I have 2 variants for that in my mind: they don't do anything (keep expired data), and only do check ...
65
votes
12answers
59k views

Is it a bad practice to store large files (10 MB) in a database? [closed]

I am currently creating a web application that allows users to store and share files, 1 MB - 10 MB in size. It seems to me that storing the files in a database will significantly slow down ...
1
vote
1answer
119 views

User Authentication. Database lookup vs RPC call

If we have more than one service that uses same database - is it ok to move out user authentication on separate server and use RPC calls, instead of traditional database lookup?
3
votes
5answers
436 views

New application development - Use existing database or create a new one?

A Client has a huge Windows Application running on a Database. This client wants you to develop an "Express" version of this application, including only, let's say, 20% of its features. This Express ...
1
vote
1answer
6k views

how to compare two large sets of data using PL/SQL?

I have two different tables in two separate databases with around 1.5 million records each. (BTW: im working on oracle databases) The objective is to check if every record present in table A is ...
4
votes
6answers
2k views

How do you handle database security from a desktop application?

For about 10 years I've worked on various in-house desktop client applications with SQL Server data stores. Rarely did I start these projects - most are takeover work. One thing that seemed constant ...
0
votes
3answers
357 views

Software design approach for large relational database

I am working on a personal side project that will utilize a complex and large relational database. During the design of the database I had some co-workers give advice to how I should approach my ...
0
votes
2answers
1k views

WCF Service in an N-tier Application

Is it recommended to use a WCF Service Library in developing an N-Tier Windows Application? Also is it better to use the VS wizards to create the DataTables and DataSets? And if so should I add all of ...
3
votes
1answer
2k views

Using WCF as an API for Database access by the GUI, or no?

Originally I asked this question on Stackoverflow but I was suggested to move the question here. I've asked this question a while ago in MSDN forums but I'd like a second opinion from ...
3
votes
4answers
378 views

How to implement a system to hide spammed user content?

I'm trying to work out a good way to manage user submitted content and create a method to determine when spammed/poor content should be hidden. The aim is to create comment voting similar to youtubes ...
2
votes
2answers
670 views

Using a DSN database connection is a bad practice?

During all my professional lifetime that I have been programming in Windows enviroments, I advised my friends and coworkers to not use a DSN database connection in their applications, based on my own ...
1
vote
1answer
162 views

DB technology for efficient search in tabular data?

We have a repository of tables. Around 200 tables, each table can be thousands of rows, all tables are originally in Excel sheets. Each table has a different scheme. All data is text or numbers. We ...
0
votes
2answers
193 views

Persistent Storage format for (update+read)-intensive data

I am developing a Java application. While using the application, data would be generated that needs to be stored on disk. I am looking for an embedded database appropriate for a average use-case of ...