Oracle 实用SQL

   -- 删除索引
   DROP INDEX "INDEX_EIS_SALE_50" ON V_DERP_SALE
  -- ALTER TABLE V_DERP_SALE DROP INDEX INDEX_EIS_SALE_50

-- 查看耗时SQL中的前10条
select *
from (select v.sql_id,
v.child_number,
v.sql_text,
v.elapsed_time,
v.cpu_time,
v.disk_reads,
rank() over(order by v.cpu_time desc) elapsed_rank
from v$sql v) a
where elapsed_rank <= 10

-- 当前会话连接数=32
select count(*) from v$process

-- 并发连接数
Select count(*) from v$session where status='ACTIVE'

-- 查看Oracle使用何种优化器
-- error
-- select * from OPTIMIZER_MODE;

select a.program, b.spid, c.sql_text, c.SQL_ID
  from v$session a, v$process b, v$sqlarea c
 where a.paddr = b.addr
   and a.sql_hash_value = c.hash_value
   and a.username is not null;
--
select * 
from v$sql
where SQL_ID = '0q7n38yy99vmz'

-- 查看用户JOB表数据
select t.job, t.this_date, t.THIS_SEC , t.TOTAL_TIME ,t.what
  from user_jobs t
  order by JOB asc
  
-- 查看正在运行的JOB
select * 
from dba_jobs_running 
--where job = '774';

-- 启动JOB
--exec dbms_job.run(666);

-- 停止JOB
--EXEC dbms_job.broken(84, true);
 
-- 查询正在执行的SQL
-- 一直再往这个表insert数据V_DERP_SEASON_STORAGE
-- 找找是哪个地方再写入,看看是不是批量操作的,不是的话改成批量操作，加快响应，规避影响其他查询SQL操作
select a.username, a.sid,b.SQL_TEXT, b.SQL_FULLTEXT
  from v$session a, v$sqlarea b 
where a.sql_address = b.address 

--查询最慢的sql
select *
  from (select parsing_user_id,
               executions,
               sorts command_type,
               disk_reads,
               sql_text
          from v$sqlarea
         order by disk_reads desc)
 where rownum < 10
 
-- 找出所有被锁的对象，定位出哪个回话占用
select o.status, l.session_id, l.OBJECT_ID, o.owner,o.object_name
from v$locked_object l,dba_objects o
where l.object_id=o.object_id

-- 检查所有回滚段状态
select segment_name,status from dba_rollback_segs;

-- 查看死锁的SQL
select sql_text
  from v$sql
 where hash_value in
       (select sql_hash_value
          from v$session
         where sid in (select session_id from v$locked_object));

-- 参看会话
select * 
from v$session t
where username is not null
AND t.SID in (42)

-- kill 所有占用资源的会话
-- 命令形式：alter system kill session 'sid,serial#';
-- 占用test_1的资源的会话：
alter system kill session '42,46316' IMMEDIATE;