oracle运维--04.查询占用物理读、等待事件、查询慢等资源性能

1.查询占用物理读资源

select sql_text,sql_id, disk_reads, buffer_gets, parsing_schema_name, executions
from v$sqlarea where parsing_schema_name='用户对象'
order by disk_reads desc;

2.查询当前执行sql

SELECT b.inst_id,b.sid oracleID,
       b.username 登录Oracle用户名,
       b.serial#,
       spid 操作系统ID,
       paddr,
       sql_text 正在执行的SQL,
       sql_fulltext,
       b.machine 计算机名,
       b.EVENT,
       'alter system kill session '''||b.sid||','||b.serial#||''';'
FROM gv$process a, gv$session b, gv$sql c
WHERE a.addr = b.paddr
   AND b.sql_hash_value = c.hash_value
   and a.inst_id=1
   and b.inst_id=1
   and c.inst_id=1
   and b.status='ACTIVE'

3.查到当前等待事件最多的sql

SELECT b.inst_id,b.sid oracleID,
       b.username 登录Oracle用户名,
       b.serial#,
       spid 操作系统ID,
       paddr,
       sql_text 正在执行的SQL,
       sql_fulltext,
       b.machine 计算机名,
       b.EVENT,
       c.SQL_ID,
       c.CHILD_NUMBER
FROM gv$process a, gv$session b, gv$sql c
WHERE a.addr = b.paddr
   AND b.sql_hash_value = c.hash_value
and event like '%gc current request%'
   and a.inst_id=1
   and b.inst_id=1
   and c.inst_id=1

4.查询执行最慢的sql-top50

select *
 from (select sa.SQL_TEXT,
        sa.SQL_FULLTEXT,
        sa.EXECUTIONS "执行次数",
        round(sa.ELAPSED_TIME / 1000000, 2) "总执行时间",
        round(sa.ELAPSED_TIME / 1000000 / sa.EXECUTIONS, 2) "平均执行时间",
        sa.COMMAND_TYPE,
        sa.PARSING_USER_ID "用户ID",
        u.username "用户名",
        sa.HASH_VALUE
     from v$sqlarea sa
     left join all_users u
      on sa.PARSING_USER_ID = u.user_id
     where sa.EXECUTIONS > 0
     order by (sa.ELAPSED_TIME / sa.EXECUTIONS) desc)
 where rownum <= 50;

5.查询次数最多的sql

select *
 from (select s.SQL_TEXT,
        s.EXECUTIONS "执行次数",
        s.parsing_schema_name,
        s.PARSING_USER_ID "用户名",
        rank() over(order by EXECUTIONS desc) EXEC_RANK
     from v$sql s
     left join all_users u
      on u.USER_ID = s.PARSING_USER_ID) t
 where exec_rank <= 100;