Core part of Temporary Table
Ø Data only visible from the current session
Added Advantages
Ø Index can be created on temporary table
Ø Check constraints is possible (unicity, limited set of possible values…)
Ø A view can reference a temporary table
Ø No FOREIGN KEY ,
no storage allocation, no INITIAL extent, no tablespace
Ø Temporary table allocates storage from the
temporary tablespace of the connected user.
Why Temporary
table is faster
Ø Temporary tables generate no redo logs for their
blocks.
What need to be
avoided while using Temporary table.
Ø Temporary tables generate undo, and the undo is
logged.
Ø So we must avoid deleting or updating from
temporary tables. You can just let the temporary tables empty themselves
automatically after a commit.
Ø If billions of rows will be inserted producing a
temporary tablespaces full, If such a process does not give performance
increase
What should we do
using Temporary table
Ø You should use temporary tables mostly for inserting or
selecting of data
