PgReports

Gem Version Ruby Rails License: MIT

A comprehensive PostgreSQL monitoring and analysis library for Rails applications. Get insights into query performance, index usage, table statistics, connection health, and more — across every database on the cluster, switchable from the dashboard with no extra configuration. Includes a beautiful web dashboard, a Grafana / Prometheus exporter, and Telegram delivery.

[!NOTE] It now runs standalone, too — launch the dashboard against any PostgreSQL database without a host Rails app, straight from the gem with a single command (pg_reports server). It still needs a Ruby runtime installed. Docker images (no Ruby required) are planned for the near future. See Standalone mode →.

Dashboard Screenshot

Features

  • 🚀 Standalone or mounted - Run inside your Rails app, or launch the dashboard on its own with pg_reports server (requires Ruby; Docker images coming soon).
  • 🗄️ Multi-database - Auto-discovers every database on the cluster and lets you switch from a dropdown in the dashboard. No configuration required.
  • 📊 Query Analysis - Identify slow, heavy, and expensive queries using pg_stat_statements
  • 📇 Index Analysis - Find unused, duplicate, invalid, and missing indexes
  • 📋 Table Statistics - Monitor table sizes, bloat, vacuum needs, and cache hit ratios
  • 🔌 Connection Monitoring - Track active connections, locks, and blocking queries
  • 🖥️ System Overview - Database sizes, PostgreSQL settings, installed extensions
  • 🌐 Web Dashboard - Beautiful dark-themed UI with sortable tables and expandable rows
  • 📨 Telegram Integration - Send reports directly to Telegram
  • 📈 Grafana / Prometheus Exporter - Expose selected reports at /metrics with severity derived from configured thresholds
  • 📥 Export - Download reports in TXT, CSV, or JSON format
  • 🔗 IDE Integration - Open source locations in VS Code, Cursor, RubyMine, or IntelliJ (with WSL support)
  • 📌 Comparison Mode - Save records to compare before/after optimization
  • 📊 EXPLAIN ANALYZE - Advanced query plan analyzer with problem detection and recommendations
  • 🖥️ SQL Console - Free-form SQL editor in a modal, run SELECT queries and view results directly from the dashboard
  • 🔍 SQL Query Monitoring - Real-time monitoring of all executed SQL queries with source location tracking (not available in standalone mode)
  • 🔌 Connection Pool Analytics - Monitor pool usage, wait times, saturation warnings, and connection churn
  • 🤖 AI Prompt Export - Copy a ready-to-paste prompt for Claude Code, Cursor, or Codex with problem context and report data
  • 🗑️ Migration Generator - Generate Rails migrations to drop unused indexes

Installation

# Gemfile
gem "pg_reports"
gem "telegram-bot-ruby"  # optional, for Telegram delivery

bundle install

Mount the dashboard:

# config/routes.rb
Rails.application.routes.draw do
  if Rails.env.development?
    mount PgReports::Engine, at: "/pg_reports"
  end

  # Or with authentication:
  # authenticate :user, ->(u) { u.admin? } do
  #   mount PgReports::Engine, at: "/pg_reports"
  # end
end

Visit http://localhost:3000/pg_reports.

For query analysis, also enable pg_stat_statements — see setup instructions in docs/configuration.md.

Standalone (no host app)

You can also run the dashboard on its own, straight from the gem's root folder — no Rails app to mount it in. It serves at / on port 4000 and connects via DATABASE_URL or libpq env vars:

./bin/pg_reports server        # from a checkout; no `bundle exec` needed
DATABASE_URL=postgres://user:pass@localhost/myapp bundle exec pg_reports server
./bin/pg_reports server --allow-raw-query-execution   # opt into the Run SQL panel

Settings come from PG_REPORTS_* env vars, an auto-detected ./pg_reports.rb config file (full PgReports.configure access), or CLI flags — in that order of precedence. Adds no runtime dependencies to the gem. Standalone guide → docs/standalone.md

Usage

# In console or code
PgReports.slow_queries.display
PgReports.unused_indexes.each { |row| puts row["index_name"] }

# Export
report = PgReports.expensive_queries
report.to_text
report.to_csv
report.to_a

Full list of reports →  ·  Send reports to Telegram →

Multi-database

The dashboard auto-discovers every database on the cluster you're connected to and shows a dropdown next to the Status panel. Switching is zero-config — credentials and host come from your existing database.yml. Schema-analysis reports stay scoped to the primary database (they introspect the host app's models); the dropdown greys them out elsewhere.

Programmatic access:

PgReports.with_database("logs")    { PgReports.table_sizes }
PgReports.with_target(:analytics)  { PgReports.slow_queries }

For multi-cluster setups (separate analytics warehouse, replica with different credentials, etc.), register additional targets explicitly. Multi-database reference in docs/configuration.md →

Configuration

PgReports works out of the box once mounted. Common options:

# config/initializers/pg_reports.rb
PgReports.configure do |config|
  config.slow_query_threshold_ms      = 100
  config.unused_index_threshold_scans = 50
  config.bloat_threshold_percent      = 20

  # Strongly recommended in production
  config.dashboard_auth = -> {
    authenticate_or_request_with_http_basic do |user, pass|
      user == ENV["PG_REPORTS_USER"] && pass == ENV["PG_REPORTS_PASSWORD"]
    end
  }
end

Multi-database, thresholds, query monitor, raw query execution, source tracking, locale — full reference in docs/configuration.md →  ·  Telegram  ·  Grafana / Prometheus

Report object

Every method returns a PgReports::Report:

report = PgReports.slow_queries

report.title         # "Slow Queries (mean time >= 100ms)"
report.data          # Array of hashes
report.columns       # Column names
report.size          # Row count
report.empty?        # Boolean
report.generated_at  # Timestamp

# Output formats
report.to_text       # Plain text table
report.to_markdown   # Markdown table
report.to_html       # HTML table
report.to_csv        # CSV
report.to_a          # Raw data

# Actions
report.display                  # Print to STDOUT
report.send_to_telegram         # Send as message
report.send_to_telegram_as_file # Send as file attachment

# Enumerable
report.each { |row| puts row }
report.map { |row| row["query"] }
report.select { |row| row["calls"] > 100 }

Dashboard features

The dashboard provides one-click execution, sortable columns, expandable rows, filter parameters, multi-format export, Telegram delivery, and pg_stat_statements management.

EXPLAIN ANALYZE — query plan analyzer

Expand a row with a query, click 📊 EXPLAIN ANALYZE. Shows:

  • Status indicator (🟢🟡🔴) — overall query health
  • Key metrics — planning/execution time, cost, rows
  • Detected problems — sequential scans on large tables, high-cost ops, sorts spilling to disk, slow sorts (>1s), inaccurate row estimates (>10× off), slow execution
  • Recommendations for each issue
  • Color-coded plan — node types tinted by performance impact (green: efficient, blue: normal, yellow: potential issue)
  • Line annotations highlighting problems on specific plan lines

Queries from pg_stat_statements with parameter placeholders ($1, $2) prompt for parameter values before analysis.

Requires config.allow_raw_query_execution = true.

SQL Console — free-form SQL editor

Click SQL Console in the header to open a large modal with a SQL editor. Type or paste a query, run it (⌘/Ctrl+Enter also works), and see the results in a table with row count and execution time.

Only SELECT statements are allowed — the same denylist validation used for the query-hash based Execute Query panel (single statement, no INSERT/UPDATE/DELETE/DROP/ALTER/CREATE/TRUNCATE/GRANT/REVOKE) applies here, since this is client-typed SQL rather than a server-generated query. See Security model for the full threat model and residual risks (this is a denylist, not a sandbox).

Every query (here and in Execute Query / EXPLAIN ANALYZE) runs under a bounded statement_timeout (config.raw_query_statement_timeout_ms, default 5s) and these endpoints are rate-limited per client IP (config.raw_query_rate_limit, default 30/min) — see Raw query execution.

Requires config.allow_raw_query_execution = true.

SQL Query Monitor — real-time query capture

Live capture of all SQL executed by your Rails app. Click ▶ Start Monitoring, run any operation, watch the queries appear with:

  • SQL with syntax highlighting
  • Duration (color-coded: 🟢 <10ms, 🟡 <100ms, 🔴 >100ms)
  • Source location with click-to-IDE
  • Timestamp

Built on ActiveSupport::Notifications (sql.active_record). Filters internal queries (SCHEMA / CACHE / pg_reports' own). Logged to log/pg_reports.log (JSON Lines). Configurable buffer size and backtrace filter:

PgReports.configure do |config|
  config.query_monitor_log_file = Rails.root.join("log", "custom_monitor.log")
  config.query_monitor_max_queries = 200
  config.query_monitor_backtrace_filter = ->(loc) { !loc.path.match?(%r{/(gems|ruby|railties)/}) }
end

Use cases: debugging N+1, identifying slow queries during feature development, tracking down unexpected queries, teaching ActiveRecord behavior.

Not available in standalone mode — there is no host application process to subscribe to, so the panel and its API are both disabled.

Connection pool analytics

Four specialized reports under the Connections category:

  • Pool Usage — total/active/idle per database, utilization %, idle-in-transaction count, available capacity
  • Wait Times — queries waiting on locks/IO/network with wait event types and severity
  • Pool Saturation — auto-classified (Normal / Elevated / Warning / Critical) with context-aware recommendations
  • Connection Churn — age distribution by application, short-lived (<10s) detection, churn-rate calculation, missing-pooling diagnosis
PgReports.pool_usage.display
PgReports.pool_saturation.display
PgReports.connection_churn.display
IDE integration & migration generator

Click any source location (file:line) in a report to open it in your IDE. Supported: VS Code, VS Code (WSL), RubyMine, IntelliJ IDEA, Cursor, Cursor (WSL). Use the ⚙️ button to set your default and skip the menu.

For unused or invalid indexes, the dashboard generates a Rails migration: expand the row → 🗑️ Generate Migration → copy the code or create the file directly (opens in your default IDE).

Save records for comparison

When optimizing queries, click 📌 Save for Comparison on any expanded row. Saved records persist in browser localStorage per report type and appear above the results table for before/after comparison.

AI prompt export

The Export dropdown includes Copy Prompt (visible on actionable reports). It assembles a ready-to-paste prompt with problem description, fix instructions, and the actual report data — formatted for Claude Code, Cursor, Codex, or any code-aware AI assistant.

Grafana / Prometheus exporter

Expose selected reports at <mount_point>/metrics in Prometheus exposition format, with severity (ok / warning / critical) derived automatically from each report's thresholds. Reports are cached per a configurable TTL so frequent scrapes don't hammer the database, and a matching Grafana dashboard can be generated from the same favorites (rake pg_reports:grafana:dashboard).

Grafana / Prometheus integration guide →  ·  Local Prometheus + Grafana without Docker →

Development

git clone https://github.com/yourusername/pg_reports
cd pg_reports
bundle install
bundle exec rspec
bundle exec rubocop

Contributing

  1. Fork it
  2. Create your feature branch (git checkout -b feature/my-feature)
  3. Commit your changes
  4. Push to the branch
  5. Create a Pull Request

License

The gem is available as open source under the terms of the MIT License.

Acknowledgments

Inspired by rails-pg-extras and built with ❤️ for the Rails community.