Storing and retrieving cache in Laravel - Performance & Optimization

Performance: Storing and retrieving cache

MEDIUM IMPACT

This affects page load speed by reducing database queries and computation time through fast data retrieval from cache.

Caching database query results to speed up page load

Laravel

<?php
$data = Cache::remember('users', 3600, fn() => DB::table('users')->get());
// Cache stores result for 60 minutes

Data is retrieved from fast cache store after first query, reducing DB hits and response time.

📈 Performance GainReduces DB queries to 1 per 60 minutes; cuts response time by 50-200ms per request

Caching database query results to speed up page load

Laravel

<?php
$data = DB::table('users')->get();
// No caching, query runs on every request

Query runs on every page load causing slower response and higher database load.

📉 Performance CostBlocks rendering for 50-200ms depending on query complexity; increases server CPU and DB load

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
No cache, direct DB query	N/A	N/A	Blocks rendering waiting for server response	[X] Bad
Cache with expiration and proper key	N/A	N/A	Fast server response enables quicker paint	[OK] Good

Rendering Pipeline

When cache is used, the server fetches data from memory or fast storage instead of querying the database, reducing backend processing time and speeding up HTML generation.

→Server Processing

→Network Transfer

→First Paint

⚠️ BottleneckServer Processing (database query time)

Core Web Vital Affected

LCP

This affects page load speed by reducing database queries and computation time through fast data retrieval from cache.

Optimization Tips

1Always cache expensive database queries to reduce server load and speed up response.

2Set appropriate cache expiration to balance freshness and performance.

3Use meaningful cache keys to avoid collisions and stale data.

Performance Quiz - 3 Questions

What is the main performance benefit of using cache in Laravel for database queries?

A Slows down page load due to cache overhead

B Increases database load by storing more data

C Reduces server response time by avoiding repeated database queries

D Has no effect on performance

DevTools: Network

How to check: Open DevTools > Network tab, reload page, check response time of API or page requests; cached responses are faster with smaller payloads.

What to look for: Look for reduced server response time and fewer database query calls in backend logs or API responses.

Practice

1. What does the Cache::put('key', 'value', 60) method do in Laravel?

easy

A. Stores 'value' permanently in cache without expiration

B. Retrieves 'value' from cache with 'key' and expires in 60 seconds

C. Deletes the cache entry with 'key' after 60 minutes

D. Stores 'value' in cache under 'key' for 60 minutes

Solution

1. Step 1: Understand Cache::put method

   The Cache::put method stores data in the cache with a key and expiration time in minutes.

2. Step 2: Analyze the parameters

   Here, 'key' is the cache key, 'value' is the data stored, and 60 means it expires after 60 minutes.

3. Final Answer:

   Stores 'value' in cache under 'key' for 60 minutes -> Option D

4. Quick Check:

   Cache::put stores with expiration = A [OK]

Hint: Cache::put stores with minutes expiry, not seconds [OK]

Common Mistakes:

• Confusing expiration time units (seconds vs minutes)
• Thinking Cache::put retrieves data
• Assuming Cache::put stores data permanently

2. Which of the following is the correct syntax to retrieve a cached value with a default fallback in Laravel?

easy

A. Cache::get('key', 'default')

B. Cache::retrieve('key', 'default')

C. Cache::fetch('key', 'default')

D. Cache::find('key', 'default')

Solution

1. Step 1: Identify Laravel cache retrieval method

   Laravel uses Cache::get to retrieve cached data safely.

2. Step 2: Check method parameters

   The second parameter is the default value returned if the key is not found.

3. Final Answer:

   Cache::get('key', 'default') -> Option A

4. Quick Check:

   Cache::get with default = A [OK]

Hint: Use Cache::get to retrieve with default fallback [OK]

Common Mistakes:

• Using non-existent methods like retrieve or fetch
• Forgetting the default fallback parameter
• Using Cache::put instead of Cache::get

3. What will be the output of this Laravel code snippet?

Cache::put('count', 5, 10);
$value = Cache::get('count', 0);
echo $value;

medium

A. 0

B. null

C. 5

D. Error

Solution

1. Step 1: Store value in cache

   The code stores the integer 5 under the key 'count' with expiration 10 minutes.

2. Step 2: Retrieve value from cache

   Then it retrieves 'count' with default 0. Since the key exists, it returns 5.

3. Final Answer:

   5 -> Option C

4. Quick Check:

   Cache::get returns stored value if exists = B [OK]

Hint: Cache::get returns stored value, not default if key exists [OK]

Common Mistakes:

• Assuming default value is always returned
• Confusing expiration time with immediate deletion
• Expecting null or error instead of stored value

4. Identify the error in this Laravel cache usage:

Cache::put('user', 'Alice');
$value = Cache::get('user');
echo $value;

medium

A. Cache::put requires expiration time as third argument

B. Cache::get requires a default value parameter

C. Cache::put key must be numeric

D. Cache::get cannot be used without Cache::forever

Solution

1. Step 1: Check Cache::put usage

   Cache::put requires three parameters: key, value, and expiration time in minutes.

2. Step 2: Identify missing expiration

   The code misses the expiration time, so it will cause an error or unexpected behavior.

3. Final Answer:

   Cache::put requires expiration time as third argument -> Option A

4. Quick Check:

   Cache::put needs expiration time = D [OK]

Hint: Always provide expiration time with Cache::put unless using forever [OK]

Common Mistakes:

• Omitting expiration time in Cache::put
• Thinking Cache::get always needs default
• Believing keys must be numeric

5. You want to store a user's settings permanently in cache and then remove them later. Which sequence of Laravel cache methods is correct?

hard

A. Cache::store('settings', $data); Cache::remove('settings');

B. Cache::forever('settings', $data); Cache::forget('settings');

C. Cache::put('settings', $data, 0); Cache::delete('settings');

D. Cache::save('settings', $data); Cache::clear('settings');

Solution

1. Step 1: Store data permanently

   Use Cache::forever to store data without expiration.

2. Step 2: Remove cached data

   Use Cache::forget to delete the cached key when needed.

3. Final Answer:

   Cache::forever('settings', $data); Cache::forget('settings'); -> Option B

4. Quick Check:

   Permanent store + forget = C [OK]

Hint: Use forever to store permanently, forget to delete [OK]

Common Mistakes:

• Using wrong method names like delete or remove
• Passing 0 as expiration to put for permanent storage
• Confusing Cache::store or Cache::save as valid methods