About The TEMP Tableplace

Question

I create only one temp tablespace which is 100M . It is engrossed only 0.08% at the begin.When I exec a SQL (Select a big table ) ,the TEMP tableplace is engrossed 99.8%.When I exit my client which exec the 'big' SQL ,the state is remain as before .When I exec the 'big' SQL again ,the TEMP tablespace increase to 203M and is engrossed 99.8%(of 203M ). When I exit my client which exec the 'big' SQL ,the state is remain as before .How to release the TEMP tablespace ?Thanks !!
If you have any answer ,please EMAIL to : vipgsp@sina. com

Answer 1

Good suggeestions above.
I'd just add that the tablespace doesn't have to be locally managed to have the segments marked free and left available for reuse. That is a function of declaring the tablespace as a type of "TEMPORARY". When you do this, once segments are allocated, they are, as noted, marked free when no longer in use. They are intentionally NOT deallocated. This avoids having to incur the overhead of deallocating and some time later, reallocating the segments (reduces the overhead). Using locally managed is a good idea since it avoids the overhead associated with updating the data dictionary when the segments are initially allocated.
Deallocation only takes place upon shutdown/startup of the database.