Mohammad Waseem

Posted on Feb 3

Mastering Query Performance Optimization in TypeScript Without a Budget

#optimization #typescript #database

Optimizing Slow Queries with TypeScript: A Zero-Budget Approach

In many legacy systems or rapidly evolving projects, database query performance becomes a bottleneck, especially when working with complex or poorly optimized queries. As a senior architect, tackling this challenge without additional resources requires strategic thinking, deep understanding of data flows, and leveraging existing tools effectively.

This article guides you through practical, budget-free strategies to identify, analyze, and optimize slow queries within a TypeScript environment.

Understanding the Root Cause

Before diving into optimization, you must understand what causes slowness. Inefficient queries, missing indexes, excessive data transfer, or unnecessary joins often contribute.

With zero additional budget, start by instrumenting your application to log all query execution times. If you're using an ORM like TypeORM or Prisma, check for built-in logging features:

// Example with Prisma
const result = await prisma.$queryRaw`
  SELECT * FROM users WHERE last_login > NOW() - INTERVAL '30 days'
`;

// Enable detailed logging
const prisma = new PrismaClient({
  log: ['query', 'info', 'warn', 'error'],
});

By activating verbose logs, you identify which queries are the slowest.

Analyzing Existing Queries

Once you pinpoint slow queries, analyze their structure:

Are they fetching unnecessary data?
Do they involve complex joins or subqueries?
Are indexes being utilized?

Use your database's explain plan feature. For example, for PostgreSQL:

EXPLAIN ANALYZE SELECT * FROM users WHERE last_login > NOW() - INTERVAL '30 days';

Review the output to find sequential scans, missing index scans, or costly sorts.

Improving Database Performance Without Extra Cost

1. Optimize Query Logic

Simplify queries by removing unnecessary joins or columns. For example:

// Original query fetching all columns
await prisma.$queryRaw(`
  SELECT * FROM orders WHERE status = 'completed'
`);

// Improved: select only needed columns
await prisma.$queryRaw(`
  SELECT order_id, total_amount FROM orders WHERE status = 'completed'
`);

2. Use Indexes Wisely

Identify which columns are used in WHERE clauses and create indexes if not present:

CREATE INDEX idx_last_login ON users(last_login);

If you lack privileges or the database is managed externally, request the DBA for adding indexes.

3. Batch and Paginate

Rewrite data fetching to limit loads per request:

const pageSize = 50;
const page = 2;
await prisma.$queryRaw(`
  SELECT * FROM messages
  ORDER BY created_at DESC
  LIMIT ${pageSize} OFFSET ${(page - 1) * pageSize}
`);

This reduces load and improves perceived responsiveness.

4. Cache Repeated Results

Implement an in-memory cache for frequently accessed data using simple JavaScript objects:

const cache = new Map<string, any>();

async function getUserData(userId: string) {
  if (cache.has(userId)) {
    return cache.get(userId);
  }
  const userData = await prisma.user.findUnique({ where: { id: userId } });
  cache.set(userId, userData);
  return userData;
}

This reduces redundant database hits.

Continuous Monitoring and Fine-Tuning

Regularly review slow queries, monitor logs, and adapt your indexes and query structures as your data grows. Remember, manual analysis and incremental improvements are powerful and cost-free.

Final Thoughts

Optimizing database queries in TypeScript without a budget hinges on meticulous analysis and incremental changes—focusing on query simplification, indexing, batching, and caching. Leveraging existing tools like your ORM's logging and explain plans empowers you to make informed decisions, ultimately resulting in a more performant application without additional investment.

Stay vigilant, measure often, and iterate wisely.

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