some easy hints for PostGRESQL
First: change user to postgres: sudo su postgres
Start the client: psql
Have a look on available databases: \l
Connect to a database: \c <databasename>
Reindex: reindex database <databasename>;
List of database users: \du
ATTENTION when upgrading to postgresql 14
You need to re-set user passwords as the hash algorithm changed:
\password "user_name"
