spool Workload_System_Statistics.sql

alter session set "_optimizer_cost_model"=cpu;

--set system statistics manually
begin
 dbms_stats.set_system_stats('cpuspeed', 1680);
 dbms_stats.set_system_stats('sreadtim', 5);
 dbms_stats.set_system_stats('mreadtim', 10);
 dbms_stats.set_system_stats('mbrc', 8);
 end;
/




explain plan for
select * from t1
where c1 between 1 and 1000;

select * from table(dbms_xplan.display);

explain plan for
select * from t1
where c1 between 1 and 2000;

select * from table(dbms_xplan.display);

explain plan for
select * from t1
where c1 between 1 and 10000;

select * from table(dbms_xplan.display);

explain plan for
select /*+ full(t1) */ * from t1
where c1 between 1 and 10000;

select * from table(dbms_xplan.display);

spool off