oracle INDEX索引性能测试

create TABLE t_service(
SerialNo VARCHAR2(20),
FilePath VARCHAR2(20),
Partid VARCHAR2(4),
StaffNo VARCHAR2(10),
RecordTime DATE
)

declare
begin
for i in 1..10000 loop
insert into t_service values('厉害3','1','2','3',sysdate);
end loop;
end;

insert into t_service values('厉害','1','2','3',sysdate);

analyze table t_service compute statistics;
set autotrace trace explain;

select SerialNo from t_service where SerialNo = '厉害';

CREATE INDEX Ix_RecordFile_SerialNo ON t_service(SerialNo) PCTFREE 30;