监视oracle执行的SQL语句(正在执行，已执行，执行性能查看)

-查询Oracle正在执行和执行过的SQL语句及语句执行性能 
1.正在执行的

select a.username, a.sid,b.SQL_TEXT, b.SQL_FULLTEXT
  from v$session a, v$sqlarea b 
where a.sql_address = b.address 

2.执行过的

select b.SQL_TEXT,b.FIRST_LOAD_TIME,b.SQL_FULLTEXT
from v$sqlarea b
where b.FIRST_LOAD_TIME between '2019-08-15/01:52:00' and '2020-02-20/13:52:02' 
order by b.FIRST_LOAD_TIME

（此方法好处可以查看某一时间段执行过的sql，并且 SQL_FULLTEXT 包含了完整的 sql 语句）
--注意格式：2019-08-15/01:52:00 可以使用  2019-08-15/1:52:00  不能使用
3.查找前十条性能差的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 ; 

4.查看占io较大的正在运行的session 
 

SELECT se.sid,se.serial#,pr.SPID,se.username,se.status, 
se.terminal,se.program,se.MODULE,se.sql_address,st.event,st.p1text,si.physical_reads, 
si.block_changes FROM v$session se,v$session_wait st, 
v$sess_io si,v$process pr WHERE st.sid=se.sid AND st. 
sid=si.sid AND se.PADDR=pr.ADDR AND se.sid>6 AND st. 
wait_time=0 AND st.event NOT LIKE '%SQL%' ORDER BY physical_reads DESC ; 

5.其他

select OSUSER,   PROGRAM,   USERNAME,   SCHEMANAME,   B.Cpu_Time,   STATUS,   B.SQL_TEXT 
from V$SESSION A
LEFT JOIN V$SQL B
ON A.SQL_ADDRESS = B.ADDRESS
AND A.SQL_HASH_VALUE = B.HASH_VALUE
order by b.cpu_time desc ;

select address, sql_text, piece 
from v$session, v$sqltext 
where address = sql_address 
order by address, piece