Database Connection

name	Database Connection
description	Connect to local or staging PostgreSQL database. Use when you need to inspect tables, run queries, check migration status, or debug database issues.

Local Database

Extract variables from .env:

grep '^DB_' .env

Parse output, construct postgresql URL, then connect:

psql "postgresql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_NAME}"

Default local connection:

PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d iota_erp

Staging Database

Extract public database URL from Railway:

railway variables -e staging -s db --kv | grep DATABASE_PUBLIC_URL

Connect using extracted URL:

psql <DATABASE_PUBLIC_URL>

Example for IOTA SDK staging:

# Get connection details from Railway
railway variables -e staging -s db --kv

# Connect (example)
PGPASSWORD=<password> psql -h <host> -U postgres -p <port> -d railway

Helper Queries

Common diagnostics after connecting:

Table Sizes

SELECT schemaname, tablename,
       pg_size_pretty(pg_total_relation_size(schemaname||'.'||tablename))
FROM pg_tables
WHERE schemaname NOT IN ('pg_catalog', 'information_schema')
ORDER BY pg_total_relation_size(schemaname||'.'||tablename) DESC
LIMIT 10;

Active Connections

SELECT datname, count(*)
FROM pg_stat_activity
GROUP BY datname;

Recent Migrations

-- Schema migrations (sql-migrate)
SELECT version, applied_at
FROM schema_migrations
ORDER BY applied_at DESC
LIMIT 5;

Database Size

SELECT pg_size_pretty(pg_database_size(current_database()));

Tenant Statistics

-- Count tenants
SELECT COUNT(*) as tenant_count FROM tenants WHERE deleted_at IS NULL;

-- Count users per tenant
SELECT t.name, COUNT(u.id) as user_count
FROM tenants t
LEFT JOIN users u ON u.tenant_id = t.id AND u.deleted_at IS NULL
WHERE t.deleted_at IS NULL
GROUP BY t.id, t.name
ORDER BY user_count DESC
LIMIT 10;

Organization Statistics

-- Count organizations
SELECT COUNT(*) as org_count FROM organizations WHERE deleted_at IS NULL;

-- Organizations per tenant
SELECT t.name, COUNT(o.id) as org_count
FROM tenants t
LEFT JOIN organizations o ON o.tenant_id = t.id AND o.deleted_at IS NULL
WHERE t.deleted_at IS NULL
GROUP BY t.id, t.name
ORDER BY org_count DESC;

Common Troubleshooting Queries

Find Long-Running Queries

SELECT pid, now() - pg_stat_activity.query_start AS duration, query
FROM pg_stat_activity
WHERE state = 'active'
  AND now() - pg_stat_activity.query_start > interval '1 minute'
ORDER BY duration DESC;

Check Table Bloat

SELECT tablename,
       pg_size_pretty(pg_total_relation_size(schemaname||'.'||tablename)) as total_size,
       pg_size_pretty(pg_relation_size(schemaname||'.'||tablename)) as table_size,
       pg_size_pretty(pg_indexes_size(schemaname||'.'||tablename)) as indexes_size
FROM pg_tables
WHERE schemaname NOT IN ('pg_catalog', 'information_schema')
ORDER BY pg_total_relation_size(schemaname||'.'||tablename) DESC
LIMIT 20;

Find Missing Indexes

SELECT schemaname, tablename, attname, n_distinct, correlation
FROM pg_stats
WHERE schemaname NOT IN ('pg_catalog', 'information_schema')
  AND n_distinct > 100
  AND correlation < 0.1
ORDER BY n_distinct DESC
LIMIT 20;

Check Lock Conflicts

SELECT blocked_locks.pid AS blocked_pid,
       blocked_activity.usename AS blocked_user,
       blocking_locks.pid AS blocking_pid,
       blocking_activity.usename AS blocking_user,
       blocked_activity.query AS blocked_statement,
       blocking_activity.query AS blocking_statement
FROM pg_catalog.pg_locks blocked_locks
JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid
JOIN pg_catalog.pg_locks blocking_locks
    ON blocking_locks.locktype = blocked_locks.locktype
    AND blocking_locks.database IS NOT DISTINCT FROM blocked_locks.database
    AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
    AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
    AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
    AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
    AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
    AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
    AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
    AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
    AND blocking_locks.pid != blocked_locks.pid
JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
WHERE NOT blocked_locks.granted;

Multi-Tenant Verification

Verify Tenant Isolation

-- Check if tenant_id is consistently applied
SELECT table_name
FROM information_schema.columns
WHERE table_schema = 'public'
  AND table_name NOT IN ('tenants', 'schema_migrations', 'sessions')
  AND table_name NOT LIKE 'pg_%'
  AND table_name NOT IN (
    SELECT table_name
    FROM information_schema.columns
    WHERE table_schema = 'public'
      AND column_name = 'tenant_id'
  );

Verify Organization Isolation

-- Check if organization_id is applied where needed
SELECT table_name, column_name
FROM information_schema.columns
WHERE table_schema = 'public'
  AND column_name = 'organization_id';

Database Maintenance

Vacuum Statistics

SELECT schemaname, tablename,
       last_vacuum, last_autovacuum,
       last_analyze, last_autoanalyze
FROM pg_stat_user_tables
ORDER BY last_autovacuum DESC NULLS LAST;

Reindex Table

-- Check for bloated indexes
REINDEX TABLE table_name;

Analyze Table

-- Update statistics
ANALYZE table_name;

Connection Tips

Using Environment Variables

# Export from .env
export $(grep '^DB_' .env | xargs)

# Connect using exported vars
PGPASSWORD=$DB_PASSWORD psql -h $DB_HOST -p $DB_PORT -U $DB_USER -d $DB_NAME

Connection Pooler

# If using pgbouncer
psql "postgresql://$DB_USER:$DB_PASSWORD@localhost:6432/$DB_NAME"

SSL Connections

# For production/staging with SSL
psql "postgresql://$DB_USER:$DB_PASSWORD@$DB_HOST:$DB_PORT/$DB_NAME?sslmode=require"

Safety Checks

Before Making Changes

-- Always verify you're on the right database
SELECT current_database();

-- Check current schema
SELECT current_schema();

-- Verify tenant context if applicable
-- (Application-level check, not SQL)

Backup Before Destructive Operations

# Dump specific table
pg_dump -h $DB_HOST -U $DB_USER -d $DB_NAME -t table_name > backup.sql

# Dump entire database
pg_dump -h $DB_HOST -U $DB_USER -d $DB_NAME > full_backup.sql

Quick Reference

# Local connection
PGPASSWORD=postgres psql -h localhost -p 5432 -U postgres -d iota_erp

# Staging connection (Railway)
railway variables -e staging -s db --kv | grep DATABASE_PUBLIC_URL
psql <DATABASE_PUBLIC_URL>

# Run query from file
psql -h localhost -U postgres -d iota_erp -f query.sql

# Export to CSV
psql -h localhost -U postgres -d iota_erp -c "COPY (SELECT * FROM users) TO STDOUT WITH CSV HEADER" > users.csv

# List all tables
\dt

# Describe table
\d table_name

# List all indexes
\di

# Quit
\q

Install Skill

SKILL.md