Catch Query Issues Before Production

Automated database performance analysis. Find N+1 queries, missing indexes, and slow patterns in seconds.

Django, FastAPI, SQLAlchemy. Free and open source. Works with PostgreSQL, MySQL, SQLite.

N+1 DetectionIdentify inefficient loop patterns
Missing IndexesFind unindexed columns
Cost AnalysisEstimate database infrastructure ROI
AI SuggestionsSpecific fixes with confidence scores

What QueryShield Detects

Automated analysis of your database queries to surface performance problems before they hit production.

N+1 queries (loops accessing foreign keys inefficiently)
Missing indexes on WHERE clause columns
SELECT * queries on large tables
Complex JOINs (3+ tables) without optimization hints
Sequential table scans instead of index lookups
Expensive SORT operations without indexes

Features

🔍

Automatic Detection

Runs during tests. Zero config. Analyzes all queries in real-time.

🤖

AI Root Cause Analysis

Get specific explanations and fix suggestions with confidence scores.

💰

Cost Estimation

See estimated database infrastructure costs and ROI of fixes.

⚡

Multi-Framework

Works with Django, FastAPI, SQLAlchemy. Any Python web framework.

📊

Production Monitoring

Optional middleware to sample and monitor real-world queries with 1% overhead.

📖

EXPLAIN Plan Analysis

Parses database execution plans to surface expensive operations.

Quick Start

Get running in 2 minutes.

Step 1: Install the CLI

pip install queryshield

Step 2: Choose Your Framework

Django

pip install queryshield-probe

Add to your settings.py:

INSTALLED_APPS = [
    'queryshield_probe',
    # ... your apps
]

Then run tests as normal: python manage.py test

FastAPI/SQLAlchemy

pip install queryshield-sqlalchemy

Use in your tests:

from queryshield_sqlalchemy import QueryShieldProbe

probe = QueryShieldProbe(session)
# ... run your test queries ...
report = probe.finalize()

Production Monitoring (Optional)

pip install queryshield-monitoring

Add middleware:

from queryshield_monitoring import QueryShieldMiddleware

app.add_middleware(
    QueryShieldMiddleware,
    api_key="optional-saas-api-key",
    sample_rate=0.01,  # 1% of queries
    slow_query_threshold_ms=500
)

Sample Report

QueryShield generates detailed JSON reports with actionable insights.

{
  "total_queries": 523,
  "problems": [
    {
      "type": "N+1",
      "sql": "SELECT * FROM books WHERE author_id = ?",
      "count": 15,
      "root_cause": "Loop accessing foreign key without prefetch",
      "suggestion": "Use select_related() or prefetch_related() to batch load related objects",
      "confidence": 95,
      "estimated_improvement": "15x faster",
      "estimated_monthly_cost": 150
    },
    {
      "type": "MISSING_INDEX",
      "sql": "SELECT * FROM users WHERE email = ?",
      "root_cause": "Email column has no index",
      "suggestion": "Add index: CREATE INDEX idx_users_email ON users(email)",
      "confidence": 92,
      "estimated_improvement": "100x faster",
      "estimated_monthly_cost": 2100
    }
  ],
  "estimated_monthly_cost": 3250,
  "recommended_fixes": [
    "Add select_related('author') to QuerySet",
    "Create index on users(email)",
    "Review complex JOIN in reports view"
  ]
}

Pro Early Access

We are building paid features for teams that need deeper visibility and automation. Leave your email if you want early access and discounts.

Planned Pro Features

Hosted dashboard with history and trends
Performance regression detection on PRs (GitHub Checks)
Alerting (Slack, email, webhooks, PagerDuty)
Cost analytics and ROI calculator
Team roles (RBAC) and API key management
On‑premise/self‑hosted option

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