Raw queries when needed in Express - Performance & Optimization

Performance: Raw queries when needed

MEDIUM IMPACT

Using raw queries affects server response time and database query execution speed, impacting how fast data is sent to the client.

Fetching complex data efficiently from the database

Express

await sequelize.query("SELECT users.*, orders.* FROM users JOIN orders ON users.id = orders.user_id WHERE orders.status = 'pending'");

Raw query executes a single optimized SQL statement reducing overhead and speeding up data retrieval.

📈 Performance Gainreduces query time by 30-50% and server blocking time

Fetching complex data efficiently from the database

Express

await User.findAll({ include: [{ model: Order, where: { status: 'pending' } }] });

ORM generates multiple queries or inefficient joins causing slower response and higher CPU usage.

📉 Performance Costblocks server response for 100-200ms on complex joins

Performance Comparison

Pattern	DOM Operations	Reflows	Paint Cost	Verdict
ORM complex queries	N/A	N/A	Higher server response delay	[X] Bad
Raw SQL queries	N/A	N/A	Lower server response delay	[OK] Good

Rendering Pipeline

Raw queries reduce server processing time, allowing faster data delivery to the browser, improving initial content paint.

→Server Processing

→Network Transfer

→Browser Rendering

⚠️ BottleneckServer Processing due to ORM overhead

Core Web Vital Affected

LCP

Using raw queries affects server response time and database query execution speed, impacting how fast data is sent to the client.

Optimization Tips

1Use raw queries for complex or performance-critical database operations.

2Always sanitize inputs in raw queries to prevent SQL injection.

3Avoid raw queries for simple CRUD operations where ORM is efficient.

Performance Quiz - 3 Questions

Why might raw SQL queries improve performance over ORM methods?

A They reduce server CPU usage by avoiding ORM overhead

B They increase the number of database queries

C They add extra parsing steps on the server

D They always cache data automatically

DevTools: Network

How to check: Open DevTools, go to Network tab, reload page, and inspect the time taken for API calls fetching data.

What to look for: Look for shorter server response times and faster data transfer indicating efficient queries.