2006/7/28, Powell, Mark D <mark.powell@xxxxxxx>:
2- you usually do not need temporary tables in Oracle. Many times #tables are used in SQL Server just because of how poorly it handles joins of 5 - 10 tables. In Oracle just do the join. Alternate features that can sometime replace a temporary table include reference cursors, piped row functions, and pl/sql collection structures.
I'd like to add subquery factoring (WITH) clause of SELECT statement to this list. In case Oracle decides it is worth to execute subquery once and reuse it several times it internally creates temporary table on the fly and stores intermediate results there. Of course it is optional scenario and subquery can be executed as many times as needed in actual select statement.
Gints Plivna http://www.gplivna.eu -- //www.freelists.org/webpage/oracle-l
