Question

我对Oracle Index有疑问。为departments表的department_name属性创建索引。证明索引将在下面的SQL语句中使用。从department_name =＆＃39; COMPUTER＆＃39;

的部门中选择*

我创建了索引，但我不确定如何证明它，因为索引无法在SQL语句中看到。

在部门（department_name）上创建索引dept.idx;

从department_name =＆＃39; COMPUTER＆＃39;

的部门中选择*

如何证明？

Answer 1

使用解释计划，它将告诉您数据库计划用于运行查询的内容，

--Generate explain plan.
EXPLAIN PLAN FOR
select * from departments where department_name='COMPUTER';

--Display explain plan.
select * from table(dbms_xplan.display);

Answer 2

ALTER INDEX dept.idx MONITORING USAGE;

select * from departments where department_name='COMPUTER'

SELECT index_name,
   table_name,
   monitoring,
   used,
   start_monitoring,
   end_monitoring
FROM   v$object_usage
WHERE  index_name = 'IDX'
ORDER BY index_name;

如何在sql语句中使用Oracle索引

2 个答案: