All Questions
712
questions
0
votes
2
answers
42
views
SQL vs NoSQL for library management system
I am creating a library management system for my first project. The primary objective is to have a management system for users who are going inside and out the library. What my plan is:
The users of ...
1
vote
2
answers
60
views
What is the most suitable data type for a column in a table?
Currently I'm trying to develop a PostgreSQL database schema, it has only 2 tables, one of which contains usernames. The difficulty is that for certain reasons I cannot store the username directly, so ...
- 1,245
0
votes
0
answers
32
views
which database is suitable
I have a postgres as main database. Couple tables are huge, they store approximately 5 million rows. So my query usually contains couple joins which are super expensive, so I decided to denormalize ...
- 23
0
votes
0
answers
28
views
How do I design data structures and choose technologies for reporting?
Problem Summary
I have multiple different applications which collate data and currently output different data files (CSV, JSON, XML). I have several reports that I am building in Power BI, which use ...
- 116
0
votes
0
answers
26
views
I have survey data with responses are encoded in numbers and the actual datamap file where the code number & actual value is present in another file
I have survey data with responses are encoded in numbers and the actual datamap file where the code number & actual value is present in another file. I want to analyse this data how to combine ...
0
votes
1
answer
46
views
Create a table in postgress on jupyter results in syntax error?
I try to create a table in postgress in my jupyter lab!
but there comes this bug!
%%bash
cat <<"EOF" | sudo docker exec -i dbis-postgres-db-1 psql -U postgres
DROP DATABASE IF ...
0
votes
0
answers
97
views
Best solution for storing 10,000,000+ lines of json objects which needs to be checked (new data inserted) daily
I have a big zip file which contains around 10,000,000+ lines of json objects. Every day I receive a new zip file which contains mostly exactly the same data but some of it (maybe around 2%) is ...
- 1
0
votes
1
answer
104
views
Common table expression (CTE) in Apache Cassandra
I had a SingleStore database and I decided to switch to Apache Cassandra, transferred all the tables with data, and decided to test the queries. Cassandra doesn't understand "WITH" Clause.
...
0
votes
0
answers
23
views
database design for react native application with in app purchase
I want to design database schemas for react native applications that have in app purchase and free with ads. Can you help me or give me a link to a document or book about that issue? I'm so grateful
...
0
votes
1
answer
41
views
Does a compound index where the prefix field is unique make any sense?
Let's take the field _id, which is unique across the collection.
Does it make any sense to have any compound index where _id is the prefix eg:
{
_id: 1,
A: 1
}
Would the index above be any more ...
0
votes
1
answer
86
views
Do transactions happen only in SQL database in Spring Boot projects?
I'm learning about SQL and NoSQL databases in Spring Boot projects. And I have a question about transactions in databases. I know that when you use @Transactional at a method, all the queries from ...
- 1,030
0
votes
2
answers
731
views
Is $lookup from MongoDB slower than a join in a SQL database, with indexes involve?
db.inventory.aggregate( [
{
$lookup:
{
from: "order",
localField: "_id",
foreignField: "item_id",
as: "...
0
votes
0
answers
18
views
Algorithm for finding top-k similar nodes in database
I'm trying to choose the right database and schemas for the following problem:
There are millions of type A nodes and type B nodes in the system. A and B nodes are disjoint and don't have direct ...
- 6,460
0
votes
1
answer
76
views
Data modelling - Nested object vs Separate DB Table
I'm designing Sticky notes Management Application (CRUD), where StickyNote has 3 attributes, heading, summary and task list. The task has 2 attributes - heading and summary.
A sticky note can have ...
- 1,096
0
votes
1
answer
566
views
How to write SQL Query in Azure cosmos DB to find search pattern of any user
Below is a sample item from azure cosmos DB container, I'm trying to write sql to get below expected output but unable to get it, can you help to write correct sql please. your help is greatly ...
- 29