Environment Variables¶

pg respects standard PostgreSQL environment variables when no explicit connection options are provided.

Supported Variables¶

Variable	Description	Example
`PGHOST`	Database server host	`localhost`
`PGPORT`	Database server port	`5432`
`PGDATABASE`	Default database name	`myapp`
`PGUSER`	Database username	`admin`
`PGPASSWORD`	Database password	`secret123`
`PGPASSFILE`	Password file location	`~/.pgpass`
`PGSERVICEFILE`	Service file location	`~/.pg_service.conf`

Usage¶

Set environment variables in your shell:

export PGHOST=localhost
export PGPORT=5432
export PGUSER=admin
export PGDATABASE=myapp

# Now pg uses these defaults
pg query
pg dump db -f dump.sql
pg maintain vacuum

Priority Order¶

pg uses connection information in this order:

Explicit options (-h, -p, -u, -d, -c, -s) - Cannot mix different connection methods
PostgreSQL defaults

Connection Method Conflicts

Using multiple connection methods together will cause pg to fail:

# ❌ This will fail
pg query -s production -h localhost

# ❌ This will also fail
pg query -c "host=server" -u admin

Common Patterns¶

Development Setup¶

# In ~/.bashrc or ~/.zshrc
export PGHOST=localhost
export PGPORT=5432
export PGUSER=dev_user
export PGDATABASE=myapp_dev

# Simple commands without connection flags
pg query
pg dump db -f daily-dump.sql

CI/CD Pipelines¶

# Set in CI environment
export PGHOST=ci-database
export PGUSER=ci_user

# Scripts work without hardcoded connections
pg info ready
pg dump db -f test-data.sql

Security Notes¶

Avoid PGPASSWORD in production - use .pgpass files or certificate auth instead
Use service files for better credential management
Environment variables are visible in process lists - prefer secure alternatives

For complete PostgreSQL environment variable documentation, see the PostgreSQL documentation.