codesnips

database

python 
import random


class ReadWriteRouter:
    """Route reads to replicas, writes to primary."""

Django database read-write split with routers

django python database
by Priya Sharma 3 tabs
python 
from blog.models import Post


# Load only specific fields
posts = Post.objects.only('id', 'title', 'published_at')
for post in posts:

Django query optimization with only and defer

django python database
by Priya Sharma 1 tab
python 
DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'mydb',
        'USER': 'myuser',
        'PASSWORD': 'mypassword',

Django database connection pooling for performance

django python database
by Priya Sharma 1 tab
typescript 
import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient();

export async function getFeedNaive(limit = 20) {
  const posts = await prisma.post.findMany({

Prisma: avoid N+1 with include/select

prisma performance typescript
by codesnips 3 tabs
rust 
use async_trait::async_trait;
use std::io;

#[async_trait]
pub trait ConnectionFactory: Send + Sync + 'static {
    type Connection: Send + 'static;

Building a Bounded Async Database Connection Pool With Tokio Semaphore

rust tokio async
by codesnips 3 tabs
yaml 
production:
  primary:
    adapter: postgresql
    database: app_production
    username: app
    password: <%= ENV["PRIMARY_DB_PASSWORD"] %>

Read Replica Routing for GET-Heavy Endpoints

rails activerecord postgres
by codesnips 4 tabs
sql 
-- INNER JOIN: Only matching rows
SELECT
  users.name,
  orders.order_number,
  orders.total
FROM users

Advanced SQL joins and query optimization

sql joins query-optimization
by Maria Garcia 2 tabs
go 
package store

import (
	"context"
	"database/sql"
)

Propagating a Context Deadline for Per-Request Timeouts in Go HTTP Handlers

go context http
by codesnips 3 tabs
python 
import sqlite3

import click
from flask import current_app, g

Request-Scoped Database Connections in Flask Using g and teardown_appcontext

flask sqlite connection-pooling
by codesnips 4 tabs
ruby 
module ConnectionHealth
  extend ActiveSupport::Concern

  def with_fresh_connection
    conn = ActiveRecord::Base.connection
    conn.verify! # pings and reconnects if the socket is dead

Keep DB Connections Healthy in Long Jobs

rails activerecord background-jobs
by codesnips 3 tabs
sql 
-- Unnormalized (0NF): Repeating groups
CREATE TABLE orders_bad (
  order_id INT,
  customer_name VARCHAR(100),
  customer_email VARCHAR(100),
  product1 VARCHAR(100),

Database normalization and schema design patterns

database normalization schema-design
by Maria Garcia 2 tabs
go 
package export

import (
	"encoding/csv"
	"log"
	"net/http"

Streaming Large CSV Exports in Go Without Buffering the Whole File

go http csv
by codesnips 3 tabs