All Questions
710
questions
1
vote
2
answers
80
views
In MongoDB, if my queries do not involve any joins, can I assume that it will scale?
I have an APP that will be demanding in terms of pulling data. Each time a user logs in, data is pulled, each time a new page is visited data is pulled, etc.
Let's suppose that these queries will ...
0
votes
2
answers
342
views
What is the time complexity of fetching data from a table that is referenced in another table?
const image_schema = () => {
const common_fields = {
user_id: {
type: mongoose.Schema.Types.ObjectId,
ref: "user",
required: true,
},
file_name: {
...
1
vote
0
answers
89
views
Equivalent query from mysql to mongodb
JOIN t2 ON t1.id=t2.id AND t1.date=t2.date
I am new to mongodb and I didn’t find a query to join two collections where I need to compare two fields from both collections.
0
votes
1
answer
618
views
In MongoDB, what is the time complexity of a query to find all records with row ids not in a given list?
I have a pre defined array, A, containing an arbitrary number of row ids for a particular table.
The query is to find all records / rows of this table that have row ids not contained in A.
What is ...
-2
votes
1
answer
814
views
Multiple tables vs one table with more columns
My chosen database is MongoDB. But the question should be independent.
So for example, each row of record will have a flag that can take 1 of 2 possible values.
What is the pro and con of:
Having 1 ...
0
votes
0
answers
115
views
Should I store an attribute with only 2 possible values has a Boolean, Number, or String in MongoDB?
So I have an attribute for a table that can either take on the values of yes or no.
What are some reasons I should store it as a Boolean: yes -> true, no -> false.
What are some reasons I should ...
0
votes
0
answers
330
views
How to make an MCD, MLD and a class diagram with Firebase Firestore?
For my defense project I made a web application with Firebase and in my report must include a conceptual data model and a logical data model, how to achieve this with a document-oriented NoSql ...
0
votes
1
answer
279
views
How to export script create database in MongoDB?
In MS SQL Server, after creating database completely, we have file script.sql and anyone want to create our database, they just need to run that file script.sql
I don't know whether if we can export ...
- 19
0
votes
1
answer
34
views
How not having the ACID properties of a Relational database helps Non-relational database perform better?
I've read that some databases sacrifices ACID properties to have a better performance and scalibility.
Why not having the ACID properties helps a database having a better performance and scalibility ...
- 515
1
vote
1
answer
107
views
Request couchbase with two where conditions
How is it possible to write a couchbase request in order to choose the first condition in where if it is defined or the second one if the first one is undefined.
I tried somethings like :
SELECT id ...
- 192
0
votes
1
answer
38
views
Retrieving any row from DB efficiently
sorry if this is a really basic question.
I am thinking about creating a simple DB that stores a large number of pre-generated key and value pair. The key operations that I'll want to perform on this ...
- 51
-1
votes
1
answer
183
views
Question about how SQL and NoSQL manage storage
I'm new to NoSQL. I have this question all the time. As we all know in SQL, data are store in tables where except the first row, are only data. In contrast, NoSQL stores data in Object, which contain ...
0
votes
1
answer
216
views
Which database fits better for a Gymlog app?
In my Gym Log App you can create an own gymplan. This plan will have a fix amount of exercises where you can note every day your stats for each exercise. Therefore every exercise can have 1-5 sets and ...
- 13
1
vote
0
answers
108
views
Proper Data model for stateful user forms using PostgreSQL
I'm building where much of the UI evolves from the user filling out and completing form wizards centered around a specific topic. I'm currently using PostgreSQL with Hasura GraphQL engine on the ...
- 101
0
votes
0
answers
36
views
Neo4j: how to filter query
I'm having trouble getting this query to work:
MATCH (pb:PRO{code: $pb, letter:$L})-[customerof:CUSTOMER_OF]->(c:CUSTOMER)-[:HAS_CONTRACT]->(con:CONTRACT)-[:HAS_POSITION]->(pos:POSITION)-[:...
- 1