Performance & Optimization

Optimize the e-commerce database for production — indexing strategies, query analysis, and performance tuning for high-traffic applications.

45 min•By Priygop Team•Last updated: Feb 2026

Performance Tuning

EXPLAIN ANALYZE: EXPLAIN ANALYZE SELECT * FROM products WHERE category_id = 5 — shows execution plan, actual time, and rows scanned. Look for 'Seq Scan' (slow) vs 'Index Scan' (fast). If Seq Scan on large table, add an index
Composite Indexes: CREATE INDEX idx_orders_user_status ON orders(user_id, status) — covers queries filtering by both columns. Column order matters: leftmost column can be used alone, but not the rightmost alone
Partial Indexes: CREATE INDEX idx_active_products ON products(category_id) WHERE is_active = true — only indexes active products. Smaller index, faster lookups for the common case (browsing active products)
Query Optimization: Replace SELECT * with specific columns (reduces I/O). Use EXISTS instead of IN for subqueries (short-circuits on first match). Avoid functions on indexed columns in WHERE (invalidates index usage)
Connection Pooling: Don't open a new database connection per request — use PgBouncer or application-level pooling. Opening a PostgreSQL connection takes 50-100ms. Pooled connections: <1ms. Critical at scale
Partitioning: CREATE TABLE orders_2024 PARTITION OF orders FOR VALUES FROM ('2024-01-01') TO ('2025-01-01') — split large tables by date range. Queries on recent orders only scan the current partition, not years of history

Try It Yourself: SQL Query Builder

Try It Yourself: SQL Query BuilderHTML

⚠ Syntax Issues (1)

⚠

Line 22: Unquoted attribute: placeholder="e.g., on line 22

💡 Wrap the value in double quotes: placeholder=""e.g.,"

HTML Editor

✓ ValidTab = 2 spaces

<!DOCTYPE html>
<html><head>
<style>
  body { font-family: Arial, sans-serif; padding: 20px; background: #f0fdf4; }
  h2 { color: #15803d; }
  .card { background: white; padding: 20px; border-radius: 10px; box-shadow: 0 2px 6px rgba(0,0,0,0.1); max-width: 580px; }
  select, input { width: 100%; padding: 8px; border: 2px solid #d1fae5; border-radius: 6px; margin: 4px 0; box-sizing: border-box; font-size: 14px; }
  label { font-weight: bold; color: #374151; display: block; margin-top: 10px; font-size: 14px; }
  button { background: #15803d; color: white; border: none; padding: 10px 20px; border-radius: 6px; cursor: pointer; font-weight: bold; margin-top: 12px; }
  .sql { background: #0f172a; color: #4ade80; padding: 16px; border-radius: 8px; font-family: monospace; font-size: 14px; margin-top: 12px; white-space: pre; line-height: 1.6; }
  .result { background: #f8fafc; padding: 12px; border-radius: 6px; margin-top: 8px; font-size: 13px; }
</style></head><body>
<div class="card">
  <h2>🔍 SQL Query Builder</h2>
  <label>Table:</label>
  <select id="table"><option>products</option><option>users</option><option>orders</option></select>
  <label>Operation:</label>
  <select id="op"><option>SELECT</option><option>INSERT</option><option>UPDATE</option><option>DELETE</option></select>
  <label>Columns (comma-separated):</label>
  <input id="cols" value="*" />
  <label>WHERE condition:</label>
  <input id="where" placeholder="e.g., price /> 100" />
  <button onclick="build()">🏗️ Generate SQL</button>
  <div class="sql" id="sql"></div>
</div>
<script>
function build(){
  const t=document.getElementById('table').value;
  const op=document.getElementById('op').value;
  const c=document.getElementById('cols').value||'*';
  const w=document.getElementById('where').value;
  let q='';
  if(op==='SELECT') q='SELECT '+c+'
FROM '+t+(w?'
WHERE '+w:'')+';';
  else if(op==='INSERT') q="INSERT INTO "+t+" ("+c+")
VALUES (/* values here */);";
  else if(op==='UPDATE') q="UPDATE "+t+"
SET "+c+" = /* new value */"+(w?"
WHERE "+w:"")+";";
  else q="DELETE FROM "+t+(w?"
WHERE "+w:"")+";";
  document.getElementById('sql').textContent=q;
}
build();
</script></body></html>

<!DOCTYPE html>
<html><head>
<style>
  body { font-family: Arial, sans-serif; padding: 20px; background: #f0fdf4; }
  h2 { color: #15803d; }
  .card { background: white; padding: 20px; border-radius: 10px; box-shadow: 0 2px 6px rgba(0,0,0,0.1); max-width: 580px; }
  select, input { width: 100%; padding: 8px; border: 2px solid #d1fae5; border-radius: 6px; margin: 4px 0; box-sizing: border-box; font-size: 14px; }
  label { font-weight: bold; color: #374151; display: block; margin-top: 10px; font-size: 14px; }
  button { background: #15803d; color: white; border: none; padding: 10px 20px; border-radius: 6px; cursor: pointer; font-weight: bold; margin-top: 12px; }
  .sql { background: #0f172a; color: #4ade80; padding: 16px; border-radius: 8px; font-family: monospace; font-size: 14px; margin-top: 12px; white-space: pre; line-height: 1.6; }
  .result { background: #f8fafc; padding: 12px; border-radius: 6px; margin-top: 8px; font-size: 13px; }
</style></head><body>
<div class="card">
  <h2>🔍 SQL Query Builder</h2>
  <label>Table:</label>
  <select id="table"><option>products</option><option>users</option><option>orders</option></select>
  <label>Operation:</label>
  <select id="op"><option>SELECT</option><option>INSERT</option><option>UPDATE</option><option>DELETE</option></select>
  <label>Columns (comma-separated):</label>
  <input id="cols" value="*" />
  <label>WHERE condition:</label>
  <input id="where" placeholder="e.g., price > 100" />
  <button onclick="build()">🏗️ Generate SQL</button>
  <div class="sql" id="sql"></div>
</div>
<script>
function build(){
  const t=document.getElementById('table').value;
  const op=document.getElementById('op').value;
  const c=document.getElementById('cols').value||'*';
  const w=document.getElementById('where').value;
  let q='';
  if(op==='SELECT') q='SELECT '+c+'
FROM '+t+(w?'
WHERE '+w:'')+';';
  else if(op==='INSERT') q="INSERT INTO "+t+" ("+c+")
VALUES (/* values here */);";
  else if(op==='UPDATE') q="UPDATE "+t+"
SET "+c+" = /* new value */"+(w?"
WHERE "+w:"")+";";
  else q="DELETE FROM "+t+(w?"
WHERE "+w:"")+";";
  document.getElementById('sql').textContent=q;
}
build();
</script></body></html>

Result

Click ▶ Run to see the result

Edit the code on the left, then click Run

HTML|46 lines|2178 chars|0 errors, 1 warning|✓ Valid syntax

UTF-8

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