While connected to a PostgreSQL database using psql, you want to toggle the timing information of some queries. Which of the following options can be used to achieve this?

You need to reload the PostgreSQL configuration without restarting the server. Which function should you use? 

In PostgreSQL, what does VACUUM do? 

You are writing an initialization script to help your team in creating a new database cluster. You want toensure that a new database cluster is initialized with md5 as the default authentication method. Which of thefollowing options of the initdb command can be used to specify the default authentication method?

You want to gracefully terminate a user's connection to the database. Which function should you use?