What is a temporary table in SQL/PLSQL? Do you use temporary tables?

A temporary table in SQL/PLSQL is a table that exists only within a session or transaction and is automatically deleted after its completion. It is used to store intermediate data that does not need to be permanently saved in the database.

In Oracle, for example, there are global temporary tables, which are created once and can be used by many sessions, but the data in them is only visible to the current session or transaction.

Using temporary tables is convenient when you need to process large volumes of data, perform complex calculations, or prepare data for further operations without affecting the main database structure.

Example of creating a temporary table in Oracle:

CREATE GLOBAL TEMPORARY TABLE temp_orders (
  order_id NUMBER,
  order_date DATE
) ON COMMIT DELETE ROWS;

Here, the data will be deleted after the transaction commit.

I use temporary tables to optimize complex queries and process intermediate results when it is justified from a performance and application logic perspective.