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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2answers
148 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 ...
0
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1answer
97 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
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3answers
357 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, ...
12
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7answers
2k 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 ...
0
votes
1answer
284 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 ...
2
votes
2answers
108 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
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0answers
60 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
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0answers
32 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 ...
11
votes
4answers
356 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 ...
0
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0answers
172 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 ...
3
votes
3answers
103 views

Should custom data elements be stored as XML or database entries?

There are a ton of questions like this, but they are mostly very generalized, so I'd like to get some views on my specific usage. General: I'm building a new project on my own in Django. It's focus ...
1
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2answers
95 views

How can you predict the time it will take for two processes in two different machines in a cluster to communicate?

I am trying to develop a computing application which needs a lot of memory (>500gb). Buying a single machine for that is overly expensive. I can, though, buy ~100 small instances on Digital Ocean or ...
0
votes
0answers
85 views

Appropriate design / technologies to handle dynamic string formatting?

recently I was tasked with implementing a way of adding support for versioning of hardware packet specifications to one of our libraries. First a bit of information about the project. We have a ...
1
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1answer
53 views

storing map template in database

I am working on an application that displays choropleth maps. These maps are of all different types, some display state by county, country by state/province, or world by country. How should I ...
0
votes
0answers
70 views

Converting large files in python

I have a few files that are ~64GB in size that I think I would like to convert to hdf5 format. I was wondering what the best approach for doing so would be? Reading line-by-line seems to take more ...
-1
votes
1answer
76 views

Storing a looong lookup table

Background The product i am working on has a very long lookup-table. the table contains static data and cannot be auto generated. there are about 500 rows and 10 columns. columns have mostly integers ...
4
votes
1answer
111 views

Synthetic database records

Assume we are getting some statistics from a customer which we analyse and we send our comments to the customer. Now, the customer tells us that the statistic they computed between January and March ...
0
votes
2answers
67 views

Is it good practice to keep 2 related tables (using auto_increment PK) to have the same Max of auto_increment ID when table1 got modified?

This question is about good design practice in programming. Let see this example, we have 2 interrelated tables: Table1 textID - text 1 - love.. 2 - men... ... Table2 rID - textID 1 - ...
0
votes
1answer
984 views

Inserting data to database from Android

I have to build an application where the requirement is that my clients will send data from their Android device and I have to save that data to a database. I have done the part of coding that ...
0
votes
1answer
161 views

Can I use access used by Visual Basic for building a database [closed]

I am the only programmer where I work (summer job) and I am a student with only a few years of programming experience. So I was asked to build a database and I am very excited about this project ...
0
votes
2answers
108 views

Minimal set of critical database operations [closed]

In designing the data layer code for an application, I'm trying to determine if there is a minimal set of database operations (both single and combined) that are essential for proper application ...
3
votes
1answer
155 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 ...
31
votes
4answers
8k views

Is backing up a MySQL database in Git a good idea?

I am trying to improve the backup situation for my application. I have a Django application and MySQL database. I read an article suggesting backing up the database in Git. On the one hand I like ...
3
votes
3answers
2k 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 ...
1
vote
1answer
99 views

Ticket/Raffle DB schema

I'm working on a project that, when all boiled down, is essentially a raffle. The twist is that due to the way we've set the ticket value, a user may be casting 10,000+ tickets. Essentially, a user ...
1
vote
3answers
136 views

Store history in SQL database column

We have a database that stores the process/history of particular machines. What I mean by that is that we have "started", "updating", "shutdown", and so on for all the computers in the company. The ...
0
votes
1answer
236 views

What language is better for working with databases? [closed]

I am going to develop a software that works with different databases and I'm considering whether to use .NET languages or C++. I've known that .NET features LINQ and ADO.NET but are there features ...
0
votes
1answer
350 views

Android DB With Some Multi-Language Data

I have a SQLite Database in my Android app with a "Question" table, among others. That table contains "default" or "pre-loaded" data (in this case the questions asked by the app). Some of its columns ...
-4
votes
1answer
103 views

How do we call database table entity in Java? [closed]

For each database table, I create an entity (object) which contains all columns of the database as Class fields. Now, how do we call these entities in Java? I could not find an official term so I ...
0
votes
1answer
42 views

Using different DB Connections for different user groups in a web framework

Database designers building enterprise systems usually assign different sets of privileges to different users of DBMS. They can be as granular as needed. However, in my experience, web frameworks ...
5
votes
1answer
494 views

To Repository Or Not To Repository

When I first learnt about Domain Driven Design, I was also introduced to the repository and unit of work patterns that once seemed to be top notch for the cool kids that threw SQL queries like ...
2
votes
1answer
144 views

To which level Haskell's HDBC is lazy?

The HDBC documentation states: fetchAllRows :: Statement -> IO [[SqlValue]]Source Lazily fetch all rows from an executed Statement. You can think of this as hGetContents applied to a ...
0
votes
2answers
116 views

How to design this better?

I'm developing a system using .NET which will be used by multiple users. Because of that, I need to identify on the database which data belongs to each user. Explaining with an example, imagine I have ...
1
vote
1answer
262 views

Eventual consistency in Banking systems

I keep hearing people say Banking systems like ATM use Eventual consistency model for data synchronization, but I am wondering if it is true. Definitely the amount you withdraw might be delayed ...
0
votes
2answers
258 views

Delphi 7 using RAM for database

I have an existing database app written in D7 with apollo databases. The client has given me a fast desktop with 24gb ram Can I somehow load the database files into ram to speed up processing? With ...
1
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1answer
216 views

Advantages and disadvantages of making one DB per customer [duplicate]

I'm starting to design a web application, and I'm evaluating some decisions regarding the general structure of it. My use case is as follows: I plan to have multiple customers on a single server. ...
1
vote
3answers
162 views

what are the things to take in consideration when designing a database that likely will be distributed after some time? [closed]

We are small start-up now, we don't have a DBA. if our project succeed, it will have a lot of data that will likely need to be distributed over several machines. So we want to make that step easier, ...
1
vote
1answer
178 views

options for data analytics for time series store

I'm building an Internet of Things solution that has a number of real time feeds. I need to make a couple of design decisions with regards to the data store and reporting and looking for input. I ...
1
vote
1answer
157 views

Dropping database in Grails is too easy. How to prevent accidental drops?

I just dropped production database. It happened because I used dbCreate = "create" instead of "update" in DataSource.groovy. I was changing some domain models and wanted to update the database. ...
2
votes
1answer
487 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 ...
1
vote
1answer
191 views

Why are JOINS deprecated for a in-memory database?

Correct me if I'm misunderstanding. Refer to the following sentence: Stack Overflow copied a key part of the Wikipedia database design. This turned out to be a mistake which will need massive ...
0
votes
3answers
113 views

How should the database schema be migrated?

I am using a bunch of freelance programmers to develop a web application. We are in the early stages of development, meaning that we are making many changes to our database schema. We have one test ...
-1
votes
1answer
108 views

Appending local MySQL data to same MySQL data in web server

my IT boss wanted this scenario to be undertaken: First, we develop an Alumni program using PHP and deploy this in the web server which can be accessed by that school alumni in the web to update their ...
1
vote
1answer
221 views

Lazy Loading, DAL and BLL abstraction

I'm asking myself a question to code the right way on a new fresh project. I have a designed database and I mapped tables to equivalent POCO classes using Entity Framework 6 Code First. Then, I ...
88
votes
10answers
15k views

Why is “Select * from table” considered bad practice

Yesterday I was discussing with a "hobby" programmer (I myself am a professional programmer). We came across some of his work, and he said he always queries all columns in his database (even on/in ...
1
vote
2answers
167 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
1k views

Why doesn't MySQL have an explicit “No Limit” option for queries?

I use SQLyog Community edition and like many other SQL applications out there it puts a 1000 result limit on queries that do not have a limit provided. I am wondering why MySQL doesn't have an ...
8
votes
1answer
392 views

When allowing a user to change passwords, should I generate a new salt?

In my database, I have a column for the hashed password and the salt. My application allows users to change their password. Should I use the same salt for the password, or should I generate a new ...
0
votes
1answer
78 views

DB Design: How to link a single column to a collection of entities

I have a db design question that I am sure has been quite extensively covered but I cannot find a good answer already. The problem is how to efficiently link a single school course to a collection ...
0
votes
2answers
68 views

Trying to “combine” similar objects without doing a bazillion comparisons

In this database I have "accesses" - each access can have any number (usually less than 4, sometimes as many as 15) attributes. I also have "tickets" where N users are requesting M accesses, so I've ...