When are they useful? Justify with an example.
The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent table, a space is not allocated to a temporary table while it is established. Space will be dynamically allocated for the table as rows are inserted. The
CREATE GLOBAL TEMPORARY
TABLE command is used to create a temporary table in Oracle.
CREATE GLOBAL TEMPORARY TABLE (
) ON COMMIT {PRESERVE|DELETE} ROWS;