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Questions tagged [rdbms]

The tag has no usage guidance.

0
votes
1answer
34 views

In a parent table - Child table relation , where to store order of children

Assume a Parent -> Child relationship in RDBMS. questionnaire table and question table. question table has a foreign key questionnaire_id to store which questionnaire it belongs to. Questionaire ...
-1
votes
1answer
64 views

Combine Ids to a single field

I would like to ask if there is any powerful method we can use to combine the Id's to a single field for faster search and retrieval. My case is like this, I have a table that stores ID's of ...
0
votes
1answer
60 views

how to model 2 objects that refer to each other in the DB

Now I have 2 objects which are "PROBLEM" and "SOLUTION", obviously "SOLUTION" is a proposed solution to a given "PROBLEM", my problem is that in my business I have the following relations: 1- a "...
117
votes
14answers
33k views

Is there any technical reason why, in programming, the default date format is YYYYMMDD and not something else?

Is there any engineering reason why is it like that? I was wondering in the case of a RDBMS that it had something to do with performance, since a "YEAR" is more specific than a "MONTH", for instance: ...
0
votes
1answer
89 views

Application analytics - Logging with NoSQL/RDBMS, BigData [closed]

I need to architect a system for my company. My question is specific to logging. Part of the requirement is to log 2 kinds of data. A1. User events (Ex: UserA clicked on Button1, performed Action#21. ...
1
vote
2answers
991 views

Should I use NoSQL (MongoDB) or SQL (postgresql) database for my application?

I am planning to build a live audience interaction webapp similar to Slido as practice/fun project. User groups: admins and anonymous users Admins: login create event (define event period and ...
0
votes
1answer
84 views

Building a scalable Email Delivery system

I want to fix my current Email Delivery system which sends email using a third-party email provider and creates a record for each email sent in RDS. Functionally this is how the system behaves - A ...
1
vote
0answers
62 views

Optimistic locking vs separate lock store for background workers

I need to compute the value of a row R on a table based on rows queried on another table B. I need to do it in a queue worker because the computation of the value can be slow. A message is queued ...
0
votes
3answers
686 views

Can traditional SQL databases be fully replaced by NewSQL?

I've recently learnt about "NewSQL" databases like: Google Cloud Spanner (proprietary) Microsoft Azure Cosmos DB (proprietary) CockroachDB (open source) also see How does CockroachDB compare to ...
2
votes
1answer
41 views

How does client connect to replication server in oracle?

I have read couple of articles on google but not sure how DB client for example java application connect to clustered DB. All the articles I read says client will write at master node but will use ...
2
votes
2answers
2k views

OLTP vs OLAP - MongoDB

RDBMS design often emphasizes data normalization (especially 3 NF) for the sake of efficient transaction processing (OLTP). OLTP is the predominant use case for an RDBMS. Goals of Normalization in ...
2
votes
3answers
484 views

Using MongoDB for not scalable application?

I have mainly worked on RDBMS databases. Recently studied MongoDB and liked where we don't have to define schemas upfront. So application developers straightaway can start writing the code. Major ...
4
votes
3answers
679 views

Best Practice regarding table schema

We are discussing in team regarding best practices. For eg. there are three tables Users Groups Teams A user will create a request to join a Team or Group or to follow a Private User. A request ...
60
votes
11answers
12k views

Should I define the relations between tables in the database or just in code?

In my experience, many of the projects I have read in the past didn't have relationship definitions in the database, instead they only defined them in the source code. So I'm wondering what are the ...
2
votes
1answer
114 views

Might this be a good candidate for a graph database? [closed]

We need to create an application that must diff relationships between entities. As an example, let's say we're creating an application to model instances of a disease amongst pets, and we ...
1
vote
1answer
122 views

What is a simple way to store data for word count purposes?

I am writing a program to crawl the web and find frequently used words. What would be a good way to store the data? I was thinning of using an RDBMS with a single table (with columns 'word' and 'count'...
-1
votes
1answer
571 views

Migrating MYSQL functions and stored procedures to SQL Server

The company i'm working for is selling HRIS management software. It was built using ASP and mysql. But one of our client's demand is for it to be based on MS SQL Server. our team is made up mostly of ...
2
votes
1answer
81 views

Design activities / events logging (ex: fields update) in RDBMS

I am trying to implement a activity tracking system in Ruby on Rails for an API only application. I have a table named letter with information as follow : id (primary key) sender_id (foreign_key on ...
4
votes
0answers
517 views

RDBMS v/s NoSQL for analytics [closed]

While reading about this topic online I have found out that, in general, RDBMS are good for read heavy loads and NoSQL databases are good for write heavy workloads. This statement also seemed true ...
22
votes
4answers
3k views

Why not just make non-parameterized queries return an error?

SQL injection is a very serious security issue, in large part because it's so easy to get it wrong: the obvious, intuitive way to build a query incorporating user input leaves you vulnerable, and the ...
7
votes
3answers
487 views

Do common relational database systems work 'out of the box'? [closed]

I'm quite new to software development and whenever I come across small projects which involve storing (relational) data I always ask myself if something like a micro-blog (or any other project with ...
3
votes
5answers
2k views

Should I use BLOB or Tables for storing large data?

Problem Currently investigating a solution to improve the performance of a web application. The application works well for small projects, but faces performance issues in the UI when working with ...
1
vote
3answers
1k views

Chat-service database design

I have an android/desktop application that I'm now releasing on the web and, as there are some social aspects, I thought of adding a chat-service so users can IM as well. For this chat service, I want ...
0
votes
1answer
192 views

user verification value - where to store [closed]

Quick question as relates to database. Where would you store the value of "UserVerified"? (The one that occurs after the user has checked his email and clicked on the "Verify" link with the hash ...
0
votes
1answer
461 views

RDBMS (MySQL) logic question. How to join multiple “FRIENDS”

so this is a logic question as to creating the proper relationships in a MySQL database. What logic would you choose for the following scenario? This is a back-end for an app where people can have ...
1
vote
1answer
235 views

DB modeling for staffing demand and supply

TL;DR - I'm looking for guidance with my database design. I am concerned that my existing design is inefficient and won't be able to handle large numbers of employees. This is going to be long, so ...
4
votes
2answers
2k views

Best solution for a large database transaction

I have a COBOL CICS process running on a mainframe legacy system. The process does over 2K DMLs in a highly concurrent DB environment. After each CRUD operation, the result is used to make further ...
5
votes
2answers
1k views

Would these two scenarios be good candidates for a NoSQL database?

I've checked a few other threads around the topic and search around, I am wondering if someone can give me a clear direction as to why should I consider NoSQL and which one (since there are quite a ...
0
votes
4answers
77 views

alerting that an object cannot be deleted (due to constraints)

Assume an application with a rich domain model with many classes (e.g School, Classroom, Teacher, Student, Course, Exam, Submission, ...) linking to each other. Model and links are mapped to the ...
2
votes
1answer
274 views

What's the name of this category of variables (NEW, OLD, etc) available inside triggers?

I need to do some very specific web search, but in order to do that I need to know what's the technical name of the category/type of variables like NEW, OLD, USER ( the could be more ) that you can ...
1
vote
1answer
267 views

MongoDB: Replicate data in documents vs. “join”

Disclaimer: This is a question derived from this one. What do you think about the following example of use case? I have a table containing orders. These orders has a lot of related information ...
0
votes
3answers
519 views

Desktop GUI Client - Remote RDBMS communication

Sorry if I am asking a trivial question but I have been searching for a while without any luck. I need to design a system and I am looking for advice on the technology that should be used. The layout ...
2
votes
2answers
318 views

Lucene + Joins == RDBMS?

Now that Lucene supports joins (at indexing time and at querying time) can one use Lucene as a databse (a NoSQL one, with Eventual Consistency)? Note: I was pondering on that for sometime and this is ...
22
votes
4answers
4k views

Why many designs ignore normalization in RDBMS?

I got to see many designs that normalization wasn't the first consideration in decision making phase. In many cases those designs included more than 30 columns, and the main approach was "to put ...
13
votes
10answers
5k views

Why don't RDBMSes return joined tables in a nested format?

For example, say I want to fetch a User and all of his phone numbers and email addresses. The phone numbers and emails are stored in separate tables, One user to many phones/emails. I can do this ...
1
vote
1answer
200 views

How is data integrity maintained in a clustered environment when schema changes?

Scenario A clustered environment running N identical application nodes interacting with a single relational database. Problem Is it possible to upgrade the nodes to a new application version, which ...
11
votes
2answers
6k views

In what order are rows fetched absent ORDER BY clause?

One programmer is testing and comparing the same application which uses the same database structure, and the same data, only in two separate databases, one with Oracle 8 and one with Oracle 9. The ...
0
votes
2answers
360 views

Why should a column in a Relational Database have a single purpose?

Consider a table in which a column represents a monetary value in some cases and a link to the value of another record in other cases so that we have the following: TABLE 1 Id Product Composite 1 ...
8
votes
2answers
546 views

Is there a canonical source supporting “all-surrogates”?

Background The "all-PK-must-be-surrogates" approach is not present in Codd's Relational Model or any SQL Standard (ANSI, ISO or other). Canonical books seems to elude this restrictions too. Oracle'...
13
votes
7answers
3k views

Should a surrogate key ever be exposed to a user?

Often in a table that has no natural key, it is still useful for users to be able to have a uniquely generated identifier. If the table has a surrogate primary key (and in such a case you would ...
13
votes
4answers
838 views

Do these specific tables need surrogate keys?

Background I have this tables +-------------------------+ +------------------------+ |Airport | |Country | |-------------------------| |------------------------| |...
1
vote
1answer
620 views

Will SSD make the distinction between column oriented DB and row oriented DB obsolete? [closed]

I had a discussion with a friend about row vs column oriented RDBMS. From my understanding, these things are closely linked with the fact that there's a concrete drive head reading and writing the ...
16
votes
3answers
19k views

Why aren't Object Oriented databases used as much as Relational Databases? [closed]

I have come across many relational database management systems (RDBMS). But recently I used hibernate which made me start wondering why Object Oriented databases aren't more popular. If object ...
5
votes
1answer
1k views

What's a good scheme for multi-user database synchronization?

I'm working on a system to allow multiple users to collaborate on an online project. Everything is fairly straightforward, except for keeping the users in sync. Each user has their own local copy of ...
8
votes
5answers
3k views

Predicting advantages of database denormalization

I was always taught to strive for the highest Normal Form of database normalization, and we were taught Bernstein's Synthesis algorithm to achieve 3NF. This is all very well and it feels nice to ...
0
votes
1answer
478 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 ...
1
vote
6answers
6k views

flat files vs. RDBMS database, few read/writes, few changes

I have to handle data from long term (years, decades) climate monitoring stations. The data flow usually starts with raw data (voltages, etc.) plus quality check information (pressure, temperature, ...
4
votes
3answers
399 views

Rule of thumb for field sizes

What VARCHAR sizes should be used for first and last names, phone numbers (preferably international), email adresses, urls, dictionary words and file names? Edit: Zapped the introductory phrase to ...
-2
votes
1answer
4k views

How to draw an E-R diagram?

I am learning DBMS in my college. Recently I was given an assignment to draw a E-R Model of a Bus Reservation system which handles Reservations, Ticketing and cancellations. I understand the theory ...
12
votes
5answers
12k views

When not to use ORM and prefer stored procedures?

I am using PetaPoco micro-ORM. It is indeed very easy and secure to work with databases using ORM tools, but the only thing I hate is extra code. I used to put most of the code in the database itself ...