Questions tagged [django]
The django tag has no usage guidance.
46
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33
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ORM vs Raw Queries
I am working on a project which I want to eventually launch to the public. In past, I have Used Django which uses ORM to use databases as python models. But I also know that they add extra overhead in ...
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17
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Errors messages when pusing data with psql on existing database
So I have a remote postgres database hosted on aws's rds, for a django application. This is still in dev (though obviously would like to start trying to do things right already). I need to upload ...
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29
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Scalable database design for supporting automation / workflow
I'm trying to come up with a scalable database design that supports automation/workflow.
In my current solution, I have a trigger model that requires a field, condition value, and action.
Example ...
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1
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55
views
Create table with foreign keys blocked by other Table-level Lock
I'm not pretty sure it is database question or development-process question, but I will kindly give it a try.
When creating a new table B with foreign keys to table A, the operation tries to acquires ...
2
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1
answer
185
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Sensible max_length for Postgres db charfields
I am using Django with a Postgres backend.
In the Django models, I have to set the max_length attribute on the Charfields, then the Django ORM deals with the database in the backend. In a lot of cases,...
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43
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Storing user defined forms and their data
I'm writing an application that would have a feature similar to Google Forms.
In this feature, some end users of the system will have the ability to design custom forms. Those forms will subsequently ...
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1
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115
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Just delete 50.000.000 of rows on a PostgreSQL table and DB still very slow
sorry for my poor english.
I have a postgres DB runing on amazon RDS (db.t3.small), with django as a backend. i have made a mistake and created 50.000.000 rows. when i figure out (because queries on ...
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23
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Reduce mysql query ( Fulltext-search ) execution runtime, server-side?
VPS:
ubuntu
Django (latest)
Python3.6
Mysql
Structure :
CREATE TABLE `tablename` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`username` varchar(255) CHARACTER SET latin1 NOT NULL,
`wallpaper` ...
1
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2
answers
127
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Why is ASC 100x faster than DESC and what can I do about it?
I'm on the cusp of understanding this, but I don't understand the fix that I need. The following query takes about minute, give or take, to return 20 records:
explain (analyze, buffers)
select "...
- 373
2
votes
1
answer
175
views
Duplicate key errors in Postgres queue-like table when rows should be locked by SELECT FOR UPDATE SKIP LOCKED
I have a table called queue with items that need to be processed:
CREATE TABLE public.queue (
id serial NOT NULL
CONSTRAINT queue_pkey
PRIMARY KEY
);
Another table process ...
- 123
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1
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932
views
Vehicle database design - Type, Make, Model, Vehicle
I kindly ask you for advice, if I am correct with my DB design. I am writing an app in Django (it has its own ORM), which will use PostgreSQL.
My expectation is, that I will specify:
Type (example: ...
- 105
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1
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853
views
How to upgrade Mysql 5.5 to 5.6 without data loss on aws-ec2?
MySQL server (5.5) is running on aws-ec2 instance with following linux details
NAME="Amazon Linux AMI"
VERSION="2015.09"
ID="amzn"
ID_LIKE="rhel fedora"
...
1
vote
2
answers
226
views
Explaining recurring crash in postgresql deployment
I'm having trouble with unexpected system crashes emanating from a postgresql deployment on a moderately busy production server (Django 1.8 app deployed on DO droplet with a gunicorn application ...
- 1,689
1
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2
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2k
views
Designing a multi-tenant database for a scenario with multiple user types
I'm developing a SaaS application for recruiting which has multiple user types such as Client, Recruiter, Panellist and Owner etc. There is also a chance that the user types may increase.
The Owner ...
0
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1
answer
70
views
Why aren't read-only queries executing concurrently? [closed]
I have a Django app using either sqlite or Postgres. (I've tried both and encountered the same problem.) Requesting a particular endpoint results in a read-only query like this that takes 1.5-3 ...
1
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140
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django-admin: postgresql trigger function
I have this table in django admin site the (Student_enrollment_record),
if i select an student and update/save the Section field
and it will search the Section field on what i select on the table (...
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-1
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1
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2k
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How to downgrade sqlite3 that comes with Python and Django
So I am stuck in this problem: https://stackoverflow.com/questions/53637182/django-no-such-table-main-auth-user-old
I can't upgrade Django because many other applications are connected to it using ...
- 139
2
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1
answer
156
views
UUID as primary key and download ID
I'm designing a Django Rest Framework API with PostgreSQL. In the database I'll be recording information about documents which can be requested for download. I want the request to include a unique id, ...
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-3
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1
answer
48
views
How to copy data from a table to another in O(1) time complexity?
I have a table Customer with fields id, account_balance, etc. At the end of every month at midnight I want to copy the whole list of customers with their account balance to another table(month, year, ...
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12
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Django - Database design improvement
In a simple scenario, where I have many measurements table that describe the measurements that comes from a specific protocol and every measurement is linked to the respective parent device, I was ...
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73
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How to model complex relationship between three Models in Django
I have to model the following entities: BuildingSite, Company, Worker.
Each entity has a many-to-many relationship with the other entities, and each relationship some attributes like start_date, ...
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603
views
Building an Entity-Relationship Diagram for a Language Dictionary
I need advice on how to build entity-relationship diagram (ERD) for Language Dictionary. Since I did not build ERD before, I will try to explain and show the ultimate goal of this project below.
...
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2k
views
Authintcation error 28000 + 18456
I have been trying to link my mssql database to Django. When I run the Django server I get the error below. For normal query (out of Django), it works fine, however, the Django doesnt even connect. ...
- 139
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682
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django_session table killing my MySQL server and django app
I need your help
I hav a Django app that is about 7 years old and have been degrading now..every time the website goes down and back up and the issue is with mysql server
Usually i need to just ...
- 335
4
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702
views
Database Design for tracking user flow
I want to design a user tracking system between different tables/models. I want to track the user's progress. There is a Module table which is related to sections and sections are related to sub-...
- 141
1
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0
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182
views
Why my heap read/heap hit ratio is negative?
I have a database with 200k rows (one of this column is a jsonb data type column), i'm using this database to store some various devices informations (currents, pressure, etc...) and i'm using this ...
- 171
1
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0
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418
views
PGPool II + Django w/ psycopg2 load balancing
I've a pool of applications running django 1.6 with psycopg2 on top of a PGPool II with two backends PostgreSQL servers. But all queries (read and/or write) are going to master PostgreSQL even SELECT.
...
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1
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0
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72
views
Scalable way to manage aggregated statistics over time in hierarchy?
I'm using a closure table (Postgres through Django) to roll up stats through a hierarchical tree. When a node that is 10 layers deep has a value that increases, each parent's sum total of that value ...
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5
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2
answers
7k
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Django postgres multiple schema
I'm trying to develop a django interface for an existing postgresql db, the db makes use of various schemas, looking at the literature the following example should work, but it only returns the schema ...
- 197
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14k
views
How to fix all duplicate key values from sequences?
I have a Postgres database that I created with a Django application. When I transferred it over, it never reindexed anything and it gives me errors trying to do this. It seems as if there are lots of ...
- 111
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79
views
Mongo DB Memory Utilisation freezes app needs restart
I am running a project using Mongo DB and Django, I have 2 separate instance for my Django project and database each 16GB ram t2xlarge ubuntu ec2 instances.
I am facing issue that within a day or two ...
3
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1
answer
138
views
Modelling a database for a travelling business that involves Vehicules, Routes, Subroutes and Prices
I am working on travelling app, where users can book online vehicles to travel.
On the customer side I would like this flow:
Users have to select a from location and a to location
Enter how many ...
- 131
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1
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1k
views
MySQL select returns no rows while there are many
I'm using django to create a database and I manually created a test values in the database by creating objects and saving them to the database.
Now when I run this query:
select TABLE_NAME,
...
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1
vote
2
answers
5k
views
Psycopg2 - PGBouncer - Postgresql > Server does not support SSL but SSL was required
I've setup my Django application to use SSL while connecting to the Postgresql database via pgbouncer. I'm using Psycopg2 library.
I've done this before successfully, so I just did the same steps ...
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2
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2
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292
views
Getting Postgres CREATE TABLE statements
I created some tables (9, to be exact) with a Django (1.9.6) migration and now I'm trying to get simple CREATE TABLE statements for them. I tried this answer, but using pg_dump in this way gives me ...
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57
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Concurrent usage of rdbms, write 4K rows without lockdown [closed]
I am working on a django project using Postgresql. The use case is as follows:
A user needs to upload an excel (containing 2.5-4K rows) 2-3 times daily. There will be 100s of users (somewhere between ...
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1
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1k
views
MySQL query taking a long time
I have a performance issue with a MySQL query that takes a long time. I'm trying to figure out why.
I'm using Django, a web framework that comes with ORM (Object relational Mappers) and basically ...
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2
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1
answer
125
views
Field/datatype for searchable address components?
I'm using Django with Postgres, and I'm looking for a field/datatype to store address components that come from Google Places API in this format:
"address_components": [
{"long_name": "27", "...
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1
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1
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92
views
Are lots of columns or joins better in Django
I am writing a simple Django app that stores and displays user objects with lots of attributes.
The user may have up to three hundred attributes.
These attributes however, can be grouped off.
For ...
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1
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3k
views
AWS Postgres RDS dumping data into sql format
My team has hosted a django project in AWS with a Postgres RDS instance. What is the proper way to get export the database into SQL or pg_dump?
- 103
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1
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505
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Django Multi Table Inheritance and Preserving Child and Child History
Place can have many different one to one fields, that’s why it can have bookstore, restaurant, and hardware store. But can the same place be both a bookstore and a restaurant at the same time? Now if ...
- 319
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41
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Make a boolean false after every n number of minutes in MySQL
I have a table with a boolean value, if that value is not explicitly set to anything in the database for a few minutes by the back-end (django) then it must automatically be set to false. How do I do ...
user93897
2
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1
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194
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Postgresql tables seem duplicated (with suffixes such us pkey, hashes, etc)
due to some problems I came to check the state of my current database in production and I found that some tables are "duplicated". By duplicated I mean that there appear to be some clones of the ...
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31
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Great slowdown of Django object list retrieval after moving from sqlite3 to mySQL on Amazon RDS
Be warned, there will be some Python programming stuff; my problem is tightly connected to database engine differences though - or at least I think so.
tl;dr: Querying for list of items and all ...
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3
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1
answer
3k
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Database in postgresql with missing rows, how to fill the missing rows with a backup copy?
I have a big problem and I'm not that good with postgresql since I use Django to make queries and I only have the basics of sql for querys.
My problem is that there was a problem where a super user ...
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592
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Django Auth user as well as custom users table?
So we've been using djangos database authentication for a while now and have recently decided we want to implement a completely new login system for our website.
We are keeping the django ORM as we ...
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