Oracle 임시테이블

두가지 형태에 임시테이블이 있으며 ms-sql처럼 스키마까지 없어지지는 않는다.
필요없게되면 drop을 시켜야 함.
오라클은 (1)세션동안에만 존재하는 테이블/(2)트랜젝션동안에만 존재하는 테이블이 있음

(1) 세션을 기동하고 테이블을 생성하여 사용하며 그 세션을 종료하면 데이타가 사라지는 테이블.

create global temporary table table_name (컬럼...) 
on commit preserve rows; 
또는 
create global temporary table table_name 
on commit preserve rows 
as select * from table;

(2)트랜젝션에서만 존재하는 즉 commit문을 만나면 데이타가 사라지는 테이블. 

create global temporary table table_name (컬럼...) 
on commit delete rows; 
또는 
create global temporary table table_name 
on commit delete rows 
as select * from table;