relational-database Questions
6
Solved
Although one can use composite primary keys, for the case below, is it really a bad practice? The consensus on Stackoveflow seems to go both ways on this issue.
Why?
I want to store payments for t...
Grille asked 27/9, 2014 at 19:46
2
Solved
In High Performance Java Persistence book's 6.3.3.3 section it's written that Lost Update phenomena is possible in MySQL Repeatable Read isolation level. This is the screenshot:
Assuming the fol...
Toughminded asked 30/11, 2018 at 18:17
6
Solved
Is it possible/are there tools/ best practices etc to migrate data to a NoSQL format from a relational DB.
I have a JEE6 app making use of Hibernate ORM to persist to MySQL but now we wish to move...
Contrivance asked 24/7, 2013 at 11:7
10
Solved
Given the task of storing international geographic addresses in a relational table, what is the most flexible schema? Should every part of the address be broken out into their own fields, or should...
Strophe asked 21/7, 2009 at 15:1
3
Solved
Most of the reasons for using a graph database seem to be that relational databases are slow when making graph like queries.
However, if I am using GraphQL with a data loader, all my queries are f...
Basle asked 2/5, 2018 at 12:18
8
Solved
Recently I've been working a little with MongoDB and I have to say I really like it. However it is a completely different type of database then I am used. I've noticed that it is most definitely be...
Antarctica asked 19/5, 2010 at 13:52
15
Solved
What is the real difference between one-to-many and many-to-one relationship? It is only reversed, kind of?
I can't find any 'good-and-easy-to-understand' tutorial about this topic other than this...
Roslynrosmarin asked 5/1, 2011 at 7:23
3
Solved
Say there is a database for students and professors (a very simple one) and the relational database is the following:
GradStudent (_id_, name, gradStuff)
UndergradStudent (_id_, name, underGradStu...
Protract asked 29/9, 2014 at 3:11
4
Solved
I've considered creating a Vertices table and an Edges table but would building graphs in memory and traversing sub-graphs require a large number of lookups? I'd like to avoid excessive database re...
Cribbs asked 3/9, 2013 at 5:19
3
Solved
I wanted to know what is the equivalent in GROUP BY, SORT BY and ORDER BY in algebra relational ?
Apocopate asked 23/2, 2015 at 1:21
1
Solved
I have the following diagram that I made to show Books and People that have relationships to them:
There are two nodes:
Person
Book
And Three relationships (with their properties, not shown in t...
Phytoplankton asked 27/12, 2021 at 4:20
1
Solved
For now, I have a working ListView that successfully loads every "parent" object in the ListView, retrieving the parent attributes and showing them in every element. Due to I am trying to...
Workbench asked 25/10, 2021 at 13:6
1
I've been trying to install mysql using WSL and I've followed the steps indicated in this guide https://learn.microsoft.com/en-us/windows/wsl/tutorials/wsl-database. I tried running mysql --version...
Outbuilding asked 7/4, 2021 at 8:3
5
Solved
in a relational database, can we have a table without any relation with the other tables?
Rutger asked 11/1, 2014 at 18:14
8
Working with databases, how can I find MAX using relational algebra?
Groscr asked 30/3, 2011 at 23:30
14
Solved
Sorry for that noob question but is there any real needs to use one-to-one relationship with tables in your database? You can implement all necessary fields inside one table. Even if data becomes v...
Knickerbockers asked 7/9, 2012 at 13:15
3
Solved
Assume a simple database for hotel reservations with three tables.
Table 1: Reservations
This table contains a check-in and check-out date as well as a reference to one or more rooms and a coupon ...
Mullite asked 4/11, 2011 at 11:22
5
Solved
Recently I've been playing around with Node.js a little bit. In my particular case I wound up using MongoDB, partly because it made sense for that project because it was very simple, and partly bec...
Fireboard asked 22/8, 2013 at 9:8
7
Solved
Consider this table:
+-------+-------+-------+-------+
| name |hobby1 |hobby2 |hobby3 |
+-------+-------+-------+-------+
| kris | ball | swim | dance |
| james | eat | sing | sleep |
| ...
Endarch asked 3/10, 2011 at 9:20
6
Solved
Considering a system that has the following characteristics:
Stores time series data/metrics collected from multiple sensors/inputs.
Data points (metrics) are collected from many different system...
Tetrapterous asked 22/2, 2019 at 9:14
4
I am asking this question in the context of DRF but this can be generalized too. We are maintaining an API service where we are serving 1K+ real-time requests. In the current scenario, we are count...
Lacrosse asked 2/5, 2021 at 19:15
3
Back when I started with database design, for some reason it was recommended that you always use snake case (my_table_name) for tables and columns. I think this was especially true in MySQL. The re...
Unstopped asked 29/4, 2013 at 21:31
3
I have two tables the posts table and the categories table.
Each post has one category only.
What I am trying to do
Connect each post with one category ID without a foreign key.
Why I am t...
Fossilize asked 11/3, 2017 at 10:50
5
Solved
I'm trying to take a look at locks that are happening on
specific tables in my PostgreSQL database.
I see there's a table called pg_locks
select * from pg_locks;
Which seems to give me a bunch ...
Aquarium asked 9/5, 2016 at 7:39
4
I am having an application where different users may connect to different databases (those can be either MySQL or Postgres), what might be the best way to cache those connections across different d...
Hasheem asked 4/11, 2020 at 0:22
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