race-condition

class AddUniqueIndexToTags < ActiveRecord::Migration[7.1]
  disable_ddl_transaction!

  def up
    execute <<~SQL
      UPDATE tags SET name = LOWER(TRIM(name)) WHERE name IS NOT NULL;

Safer “find or create” with Unique Constraint + Retry

rails activerecord concurrency

by codesnips 3 tabs

python

import uuid
from django.db import models


class Cart(models.Model):
    OPEN = "open"

Prevent Duplicate Order Submissions in Django with select_for_update Row Locking

django postgres concurrency

by codesnips 3 tabs