Postgres and Open Source Experts

To uninstall PostgreSQL from CentOS, execute the “yum remove postgresql-server postgresql-contrib” command.

In PostgreSQL, the SELECT INTO statement creates a new table, copies data from the original table, and pastes it into the newly created table.

Postgres has a built-in Window function called RANK() that assigns a rank to every single row within a partition.

A subquery in PostgreSQL is nothing more than a query within another query. It is also called a nested query, inner query, or inner select.

In PL/pgSQL, the record types are used to create the variables that can store a complete row/record of a result set.

In Postgres, the “ROW_NUMBER()” function is used with the OVER clause to operate on a set of rows and assigns a unique integer to each row.

In Postgres, constants are nothing but immutable or unchangeable variables. Once a constant is initialized with a value, it stays the same throughout the program.

PostgreSQL supports a “PL/pgSQL SELECT INTO” statement that assists us in storing the table's data into a specific variable.

In PostgreSQL, the SET SEARCH_PATH command is used to set the schema search path. The “SHOW” command is used to demonstrate the current schema search path.

The inbuilt date functions like NOW(), CURRENT_TIMESTAMP, and LOCALTIMESTAMP, are used with the INSERT statement to add the current timestamp into a Postgres table.