Curiosidades de PLSQL - exec keyword

this is the first one:

var a number
exec :a := 1
exec for a in 1..10 loop null; end loop;

this is another one:

exec open :cur for select * from dual;

this is to generate lots of gets:

desc sydney_demo1
desc sydney_demo2
desc sydney_demo3

alter session set plsql_optimize_level=0;

set timing on
exec for i in 1..&1 loop insert into sydney_demo1 values (0); end loop;

set timing off termout off
rollback;
alter system checkpoint;
set timing on  termout on

exec for i in 1..&1 loop insert into sydney_demo2 values (i); end loop;

set timing off termout off
rollback;
alter system checkpoint;
set timing on  termout on

exec for i in 1..&1 loop insert into sydney_demo3 values (i); end loop;

set timing off termout off
rollback;
alter system checkpoint;
set timing on  termout on

set timing off