In this chapter, we will cover the following recipes:
- The PostgreSQL superuser
 - Revoking user access to a table
 - Granting user access to a table
 - Granting user access to specific columns
 - Granting user access to specific rows
 - Creating a new user
 - Temporarily preventing a user from connecting
 - Removing a user without dropping their data
 - Checking whether all users have a secure password
 - Giving limited superuser powers to specific users
 - Auditing database access
 - Always knowing which user is logged in
 - Integrating with Lightweight Directory Access Protocol (LDAP)
 - Connecting using SSL
 - Using SSL certificates to authenticate
 - Mapping external usernames to database roles
 - Encrypting sensitive data