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How to Install PostgreSQL on CentOS?

To install PostgreSQL on CentOS, execute the “sudo yum install postgresql-server postgresql-contrib” script.

How to Use CARDINALITY() Function in PostgreSQL?

In PostgreSQL, CARDINALITY() is an array function that counts the total number of array elements. The return type of the stated function is INT.

How to Restart PostgreSQL Server on Windows

In PostgreSQL, the “pg_ctl” command and “services manager” can be used to restart the Postgres server on the Windows operating system.

How to Lock or Unlock a PostgreSQL User

To lock a Postgres user, the “ALTER USER” statement can be used with the “NOLOGIN” clause. While a user can be unlocked by using the “ALTER USER” command with the “LOGIN” attribute.

How to Check if a User is Connected to the PostgreSQL Server or Not

In Postgres, to check the active users via the “pg_stat_activity”, use the “SELECT usename, datname, state FROM pg_stat_activity WHERE usename='user_name';” command.

How to Grant Permissions on all Tables to a PostgreSQL User

In PostgreSQL, the GRANT statement is utilized along with the “ON ALL TABLES” clause to assign permissions on all tables to single or multiple users.

How to Change the Table Owner in PostgreSQL

To change or modify the table’s owner in PostgreSQL, use the “ALTER TABLE tab_name OWNER TO new_owner_name;” command.

How to Grant All Privileges on Schema to User in PostgreSQL

In PostgreSQL, the “GRANT ALL” statement is utilized along with the “ON ALL TABLES IN SCHEMA” clause to assign permissions on the schema to single or multiple users.

How to Get the List of Privileges Assigned to a Table in PostgreSQL

In PostgreSQL, the “\z” command and “information_schema” can be used to check the list of assigned privileges to a certain Postgres table.

How to Get or Check Table Structure in PostgreSQL

In PostgreSQL, the “\d”, the “\d+”, “information_schema”, and the “SELECT *” statement with the “FALSE” option are used to check the table’s structure.