Complete Laravel Database Performance and Debugging Guide

laravel database performance optimization caching

Optimize your Laravel application's database performance with this comprehensive guide covering query debugging, caching strategies, performance monitoring, and optimization techniques.

Database Query Debugging
Query Optimization Techniques
Caching Strategies
Performance Monitoring
N+1 Query Prevention
Database Configuration
Best Practices

Database Query Debugging

Laravel Debug Bar Integration

The most comprehensive way to monitor database queries during development:

composer require --dev barryvdh/laravel-debugbar

The debug bar provides:

Query count and execution time
Duplicate query detection
N+1 query identification
Memory usage tracking

Custom Query Logging

For production debugging or CLI scripts, implement custom query logging:

// In AppServiceProvider boot() method
DB::listen(function ($query) {
    Log::info('Database Query', [
        'sql' => $query->sql,
        'bindings' => $query->bindings,
        'time' => $query->time . 'ms'
    ]);
});

Separate Query Log File

Create a dedicated query log for easier analysis:

DB::listen(function($query) {
    File::append(
        storage_path('/logs/query.log'),
        sprintf(
            '[%s] %s [%s] %sms%s%s',
            date('Y-m-d H:i:s'),
            $query->sql,
            implode(', ', $query->bindings),
            $query->time,
            PHP_EOL,
            PHP_EOL
        )
    );
});

Conditional Query Logging

Enable query logging only in specific environments:

if (app()->environment(['local', 'staging'])) {
    DB::listen(function ($query) {
        if ($query->time > 100) { // Only log slow queries
            Log::warning('Slow Query Detected', [
                'sql' => $query->sql,
                'time' => $query->time . 'ms',
                'bindings' => $query->bindings
            ]);
        }
    });
}

Query Optimization Techniques

Eager Loading

Prevent N+1 queries with proper eager loading:

// Bad: N+1 query problem
$users = User::all();
foreach ($users as $user) {
    echo $user->profile->name; // Executes N queries
}

// Good: Eager loading
$users = User::with('profile')->get();
foreach ($users as $user) {
    echo $user->profile->name; // Single query
}

Lazy Eager Loading

Load relationships after the initial query:

$users = User::all();

// Lazy eager load when needed
$users->load('posts', 'comments');

Limiting Eager Loaded Relationships (Laravel 11+)

$posts = Post::with([
    'comments' => fn ($query) => $query->limit(5)
])->get();

Query Constraints

Add constraints to eager loaded relationships:

$users = User::with([
    'posts' => function ($query) {
        $query->where('published', true)
              ->orderBy('created_at', 'desc');
    }
])->get();

Database Indexes

Ensure proper indexing for frequently queried columns:

// Migration
Schema::table('posts', function (Blueprint $table) {
    $table->index('user_id');
    $table->index(['status', 'published_at']);
    $table->index('slug');
});

Caching Strategies

Query Result Caching

Cache expensive query results:

$expensiveData = Cache::remember('expensive_query', 3600, function () {
    return DB::table('analytics')
        ->join('users', 'users.id', '=', 'analytics.user_id')
        ->where('created_at', '>=', now()->subDays(30))
        ->get();
});

Model Caching

Implement automatic model caching:

class User extends Model
{
    protected static function booted()
    {
        static::retrieved(function ($user) {
            Cache::put("user.{$user->id}", $user, 3600);
        });

        static::saved(function ($user) {
            Cache::forget("user.{$user->id}");
        });

        static::deleted(function ($user) {
            Cache::forget("user.{$user->id}");
        });
    }

    public static function findCached($id)
    {
        return Cache::remember("user.{$id}", 3600, function () use ($id) {
            return static::find($id);
        });
    }
}

Cache Tags for Grouped Invalidation

Use cache tags to invalidate related cache entries:

// Store with tags
Cache::tags(['users', 'posts'])->put('user.posts.1', $posts, 3600);

// Invalidate all user-related cache
Cache::tags(['users'])->flush();

Authenticated User Caching

Cache the authenticated user to reduce database calls:

// Custom User Provider
class CacheUserProvider extends EloquentUserProvider
{
    public function retrieveById($identifier)
    {
        return Cache::remember("auth.user.{$identifier}", 3600, function () use ($identifier) {
            return parent::retrieveById($identifier);
        });
    }
}

// Register in AuthServiceProvider
Auth::provider('cache-user', function ($app, array $config) {
    return new CacheUserProvider($app['hash'], $config['model']);
});

// Update config/auth.php
'providers' => [
    'users' => [
        'driver' => 'cache-user',
        'model' => App\Models\User::class,
    ],
],

Performance Monitoring

Database Query Analysis

Monitor query performance in production:

DB::listen(function ($query) {
    if ($query->time > 1000) { // Queries over 1 second
        Log::critical('Very Slow Query', [
            'sql' => $query->sql,
            'time' => $query->time,
            'bindings' => $query->bindings,
            'backtrace' => debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS)
        ]);
    }
});

Memory Usage Tracking

Monitor memory consumption:

class DatabasePerformanceMiddleware
{
    public function handle($request, Closure $next)
    {
        $startTime = microtime(true);
        $startMemory = memory_get_usage();
        $queryCount = 0;

        DB::listen(function () use (&$queryCount) {
            $queryCount++;
        });

        $response = $next($request);

        $endTime = microtime(true);
        $endMemory = memory_get_usage();

        Log::info('Request Performance', [
            'url' => $request->fullUrl(),
            'method' => $request->method(),
            'execution_time' => ($endTime - $startTime) * 1000 . 'ms',
            'memory_used' => ($endMemory - $startMemory) / 1024 / 1024 . 'MB',
            'query_count' => $queryCount
        ]);

        return $response;
    }
}

N+1 Query Prevention

Detecting N+1 Queries

Use Laravel's built-in detection:

// In AppServiceProvider boot() method
Model::preventLazyLoading(! app()->isProduction());

Custom N+1 Detection

class N1QueryDetector
{
    protected static $queryCount = 0;
    protected static $models = [];

    public static function start()
    {
        static::$queryCount = 0;
        static::$models = [];

        DB::listen(function ($query) {
            static::$queryCount++;

            if (static::$queryCount > 10) {
                Log::warning('Potential N+1 Query Detected', [
                    'query_count' => static::$queryCount,
                    'sql' => $query->sql
                ]);
            }
        });
    }
}

Eager Loading Solutions

// Load multiple relationships
$posts = Post::with(['user', 'comments', 'tags'])->get();

// Nested relationships
$posts = Post::with(['comments.user', 'user.profile'])->get();

// Conditional eager loading
$posts = Post::with([
    'comments' => function ($query) {
        $query->where('approved', true);
    }
])->get();

Database Configuration

Read/Write Connections

Configure separate read/write database connections:

// config/database.php
'mysql' => [
    'read' => [
        'host' => [
            '192.168.1.1',
            '192.168.1.2',
        ],
    ],
    'write' => [
        'host' => [
            '196.168.1.3',
        ],
    ],
    'sticky' => true, // Enables sticky reads
    'driver' => 'mysql',
    'database' => 'database',
    'username' => 'root',
    'password' => '',
    'charset' => 'utf8mb4',
    'collation' => 'utf8mb4_unicode_ci',
],

Connection Pooling

Optimize connection usage:

// config/database.php
'mysql' => [
    'options' => [
        PDO::ATTR_PERSISTENT => true,
        PDO::ATTR_EMULATE_PREPARES => false,
    ],
],

Best Practices

1. Use Database Transactions

Wrap related operations in transactions:

DB::transaction(function () {
    $user = User::create($userData);
    $profile = Profile::create($profileData + ['user_id' => $user->id]);
    $user->assignRole('customer');
});

2. Implement Query Scopes

Create reusable query logic:

class Post extends Model
{
    public function scopePublished($query)
    {
        return $query->where('published', true);
    }

    public function scopeRecent($query, $days = 7)
    {
        return $query->where('created_at', '>=', now()->subDays($days));
    }
}

// Usage
$posts = Post::published()->recent(14)->get();

3. Use Chunking for Large Datasets

Process large datasets efficiently:

User::chunk(1000, function ($users) {
    foreach ($users as $user) {
        // Process user
    }
});

// Or with lazy collections
User::lazy()->each(function ($user) {
    // Process user one by one
});

4. Optimize Migrations

Create efficient database migrations:

Schema::table('posts', function (Blueprint $table) {
    $table->index(['user_id', 'published_at']);
    $table->index('slug');

    // Add foreign key constraints
    $table->foreign('user_id')->references('id')->on('users');
});

5. Monitor Query Performance

Set up alerts for slow queries:

DB::listen(function ($query) {
    if ($query->time > config('database.slow_query_threshold', 1000)) {
        // Send alert or log
        Mail::to('[email protected]')->send(new SlowQueryAlert($query));
    }
});

Frequently Asked Questions

How do I identify slow queries in production?

Use query logging with time thresholds and monitoring tools like Laravel Telescope or custom logging middleware.

What's the difference between lazy and eager loading?

Eager loading loads relationships upfront (preventing N+1), while lazy loading loads relationships when accessed (potential N+1 problem).

How do I cache complex queries?

Use Cache::remember() with appropriate cache keys and tags. Consider using Redis for complex data structures.

When should I use database transactions?

Use transactions when multiple related database operations must succeed or fail together (data consistency).

Combine these database optimizations with other Laravel performance strategies:

Prunable Eloquent models for database cleanup
Virtual database columns for computed fields
Laravel optimize command for application caching
MySQL query optimization for advanced database techniques

Conclusion

Database performance is crucial for scalable Laravel applications. By implementing proper query logging, caching strategies, and monitoring techniques, you can ensure your application remains fast and responsive as it grows.

Start with query debugging to identify bottlenecks, implement caching for expensive operations, and use proper eager loading to prevent N+1 queries. Regular monitoring and optimization will keep your database performance optimal.

Remember: measure first, optimize second. Always profile your application to identify real bottlenecks before implementing optimizations.

Jan 25, 2024

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Complete Laravel Database Performance and Debugging Guide

#Table of Contents

#Database Query Debugging

#Laravel Debug Bar Integration

#Custom Query Logging

#Separate Query Log File

#Conditional Query Logging

#Query Optimization Techniques

#Eager Loading

#Lazy Eager Loading

#Limiting Eager Loaded Relationships (Laravel 11+)

#Query Constraints

#Database Indexes

#Caching Strategies

#Query Result Caching

#Model Caching

#Cache Tags for Grouped Invalidation

#Authenticated User Caching

#Performance Monitoring

#Database Query Analysis

#Memory Usage Tracking

#N+1 Query Prevention

#Detecting N+1 Queries

#Custom N+1 Detection

#Eager Loading Solutions

#Database Configuration

#Read/Write Connections

#Connection Pooling

#Best Practices

#1. Use Database Transactions

#2. Implement Query Scopes

#3. Use Chunking for Large Datasets

#4. Optimize Migrations

#5. Monitor Query Performance

#Frequently Asked Questions

#How do I identify slow queries in production?

#What's the difference between lazy and eager loading?

#How do I cache complex queries?

#When should I use database transactions?

#Related Laravel Performance Techniques

#Conclusion

Table of Contents