Laravel chunk() vs cursor() vs lazy() — Handle Large Data Without Crashing Your Server

Laravel chunk() vs cursor() vs lazy() — Handle Large Data Without Crashing Your Server



Tópico: Laravel chunk() vs cursor() vs lazy() — Handle Large Data Without Crashing Your Server
Categoria: Tutoriais | Programação & Tecnologia
Idioma Principal: Português (Conteúdo de Tecnologia)

Descrição do Conteúdo / Informações:
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If you've ever tried to process thousands of rows in Laravel and got a memory error or server timeout — this article is for you.

I learned this the hard way when a large CSV export caused Apache timeout errors in production. Here's what I found out.



The Problem


// ❌ This will crash on large tables
$users = User::all();
foreach ($users as $user) {
// process...
}

all() loads every row into memory at once. On 100,000+ rows, your server will run out of memory.



1. chunk() — Process in Batches


User::chunk(500, function ($users) {
foreach ($users as $user) {
// processes 500 rows at a time
}
});

✅ Memory stays low

✅ Good for background jobs

⚠️ Don't modify/delete rows inside chunk() — it can skip records

⚠️ Runs multiple SQL queries

Use when: sending emails in batches, background processing



2. chunkById() — Safer Version of chunk()


User::chunkById(500, function ($users) {
foreach ($users as $user) {
// safe even when updating rows
}
});

✅ Safe to update/delete rows inside

✅ More reliable than chunk()

Use when: updating or deleting large amounts of records



3. cursor() — One Row at a Time


foreach (User::cursor() as $user) {
// processes one row at a time
}

✅ Most memory efficient

✅ Only one SQL query

❌ Can't use eager loading (with())

❌ Keeps DB connection open the whole time

Use when: read-only processing, CSV exports



4. lazy() — Best of Both Worlds


foreach (User::lazy() as $user) {
// chunks behind the scenes, feels like cursor()
}

✅ Memory efficient

✅ Supports eager loading with()

✅ Cleaner syntax

// With eager loading ✅
User::with('orders')->lazy()->each(function ($user) {
// process
});

Use when: you need cursor() but also need relationships loaded



Quick Comparison Table


Method
Memory
SQL Queries
Supports with()
Safe to modify?

all()
❌ High
1
✅
✅

chunk()
✅ Low
Multiple
✅
⚠️ No

chunkById()
✅ Low
Multiple
✅
✅ Yes

cursor()
✅ Lowest
1
❌
✅

lazy()
✅ Low
Multiple
✅
✅



My Real-World Example


This fixed my Apache timeout issue on CSV export:

// ❌ Before — caused timeout
$users = User::all();

// ✅ After — works perfectly
foreach (User::cursor() as $user) {
fputcsv($handle, [
$user->name,
$user->email,
$user->created_at
]);
}



Summary


•
chunk() — batch jobs, email sending

•
chunkById() — when modifying data in batches

•
cursor() — read-only, CSV exports, most memory efficient

•
lazy() — when you need cursor() + relationships

Want to dive deeper? Check out the full lesson on my free Laravel tutorial site 👇

https://php-laravel-tutorials.netlify.app/lesson-laravel-large-data