转http://www.dbdream.com.cn/2013/10/14/vsession_longops%E8%A7%86%E5%9B%BE/
有的时间，我们想监控 运行超过4个小时的SQL
如果是10g 版本的库，可以用 v$session_longops ，如果11g的库，推荐使用 v$sql_monitor 监视正在运行的SQL语句的统计信息，具体介绍见下文
另外使用 v$sql_monitor 也可以用来调优使用，比如查找长时间运行的SQL.具体介绍见下文
：
1.有的时候不准确 ，我看到 session wait event 一直在变化 ，也是 active 的 ，运行 时间也是48小时 以上 。但是 在 v$session_longops 显示为totalwork =0 , 无法观察 。是一条3000w 记录的update. 所以只能看v$transaction.
2.
对大部分DBA来说，V$SESSION_LONGOPS视图都不会陌生，以前在面试的时候，也有一些企业会问到如何查询数据库中运行时间比较长的SQL，就可以通过这个视图来查看。
V$SESSION_LONGOPS视图不但可以监控运行式时间比较长的SQL，也会记录RMAN备份、EXP/EXPDP、收集统计信息、排序等操作，基本数据库所有运行时间超过6秒的SQL都会记录在这个视图中，也有的DBA会定期检查这个视图来寻找可优化的SQL。
下面是这个视图的结构：
01 |
SQL> desc v$session_longops |
03 |
----------------------------------------- -------- ------------------ ------------------ |
04 |
SID NUMBER 和V$SESSION中的SID一样 |
06 |
OPNAME VARCHAR2(64) 操作的名称，如全表扫描 |
07 |
TARGET VARCHAR2(64) 被操作的对象名，如表名 |
08 |
TARGET_DESC VARCHAR2(32) TARGET的描述 |
09 |
SOFAR NUMBER 以完成的数量，如扫描多少数据块 |
10 |
TOTALWORK NUMBER 一共需要完成的数量 |
11 |
UNITS VARCHAR2(32) 计量单位 |
13 |
LAST_UPDATE_TIME DATE 最后一次调用set_session_longops的时间 |
14 |
TIMESTAMP DATE 特定操作的时间戳 |
15 |
TIME_REMAINING NUMBER 预计剩余时间，单位秒 |
16 |
ELAPSED_SECONDS NUMBER 开始操作到最后更新的时间 |
18 |
MESSAGE VARCHAR2(512) 对操作的描述 |
19 |
USERNAME VARCHAR2(30) 操作用户的名字 |
20 |
SQL_ADDRESS RAW(4) 用于关联V$SQL等视图 |
21 |
SQL_HASH_VALUE NUMBER 用于关联V$SQL等视图 |
22 |
SQL_ID VARCHAR2(13) 用于关联V$SQL等视图 |
23 |
SQL_PLAN_HASH_VALUE NUMBER 用于关联V$SQL等视图 |
24 |
SQL_EXEC_START DATE SQL开始运行的时间 |
25 |
SQL_EXEC_ID NUMBER SQL执行的标识符 |
26 |
SQL_PLAN_LINE_ID NUMBER SQL执行计划相关 |
27 |
SQL_PLAN_OPERATION VARCHAR2(30) SQL执行计划相关 |
28 |
SQL_PLAN_OPTIONS VARCHAR2(30) SQL执行计划相关 |
下面简单做几个超过6秒的操作，来查看下这个视图。
先测试下insert操作。
01 |
SQL> create table longops_test as select * from dba_objects; |
03 |
SQL> insert into longops_test select * from longops_test; |
现在INSERT操作已经超过6秒，查询下V$SESSION_LONGOPS视图。
2 |
--- ------- --------- ---------------- ----- -------- ----- --------------- ------------------- --------------- |
3 |
194 12 Table Scan SYS.LONGOPS_TEST 14895 14895 Blocks Table Scan: TABLE ACCESS FULL |
这是已经运行结束的INSERT操作，可见SOFAR和TOTALWORK的值是一样的，在看下没运行完的SQL。
1 |
SQL> create table longops_ctas as select * from longops_test; |
在SQL执行6秒后(还没运行完)时，看下V$SESSION_LONGOPS视图的状态。
02 |
--- ------- --------- ---------------- ----- -------- ----- --------------- ------------------- --------------- |
03 |
194 12 Table Scan SYS.LONGOPS_TEST 14895 14895 Blocks Table Scan: TABLE ACCESS FULL |
07 |
194 12 Table Scan SYS.LONGOPS_TEST 13275 29785 Blocks Table Scan: TABLE ACCESS FULL |
可见，当前扫描了13275个数据块，总共需要扫描29785个数据块。RMAN备份和收集统计信息也同样会被这个视图记录。
01 |
OPNAME SOFAR TOTALWORK MESSAGE |
02 |
--------------------------------- ---------- ---------- ------------------------------------------- |
03 |
Gather Table Partition Statistics 1 1 Gather Table Partition Statistics: Table |
04 |
WR H$_OSSTAT : 1 out of 1 Partitions done |
05 |
RMAN: aggregate input 1181953 1181953 RMAN: aggregate input: backup 33: 1181953 |
06 |
out of 1181953 Blocks done |
07 |
RMAN: aggregate input 1181953 1181953 RMAN: aggregate input: backup 33: 1181953 |
08 |
out of 1181953 Blocks done |
09 |
RMAN: aggregate output 359461 359461 RMAN: aggregate output: backup 33: 359461 |
10 |
out of 359461 Blocks done |
11 |
RMAN: full datafile backup 1181280 1181280 RMAN: full datafile backup: Set Count 18: |
12 |
1181280 out of 1181280 Blocks done |
下面是ORACLE官方文档对V$SESSION_LONGOPS视图的介绍：
01 |
V$SESSION_LONGOPS displays the status of various operations that run for longer than 6 seconds (in absolute time). These operations currently include many backup and recovery functions, statistics gathering, and query execution, and more operations are added for every Oracle release. |
03 |
To monitor query execution progress, you must be using the cost-based optimizer and you must: |
05 |
•Set the TIMED_STATISTICS or SQL_TRACE parameters to true |
07 |
•Gather statistics for your objects with the DBMS_STATS package |
09 |
You can add information to this view about application-specific long-running operations by using the DBMS_APPLICATION_INFO.SET_SESSION_LONGOPS procedure. |
10 |
Column Datatype Description |
11 |
------------------- ---------- --------------------------------------------------------------------------------- |
12 |
SID NUMBER Identifier of the session processing the long-running operation. If multiple sessi |
13 |
ons are cooperating in the long-running operation, then SID corresponds to the mai |
16 |
ssions are cooperating in the long-running operation, then SERIAL |
17 |
the main or master session. SERIAL |
18 |
ts. Guarantees that session-level commands are applied to the correct session obje |
19 |
cts if the session ends and another session begins with the same session ID. |
20 |
OPNAME VARCHAR2(64) Brief description of the operation |
21 |
TARGET VARCHAR2(64) Object on which the operation is carried out |
22 |
TARGET_DESC VARCHAR2(32) Description of the target |
23 |
SOFAR NUMBER Units of work done so far |
24 |
TOTALWORK NUMBER Total units of work |
25 |
UNITS VARCHAR2(32) Units of measurement |
26 |
START_TIME DATE Starting time of the operation |
27 |
LAST_UPDATE_TIME DATE Time when statistics were last updated for the operation |
28 |
TIMESTAMP DATE Timestamp specific to the operation |
29 |
TIME_REMAINING NUMBER Estimate (in seconds) of time remaining for the operation to complete |
30 |
ELAPSED_SECONDS NUMBER Number of elapsed seconds from the start of the operations |
31 |
CONTEXT NUMBER Context |
32 |
MESSAGE VARCHAR2(512) Statistics summary message |
33 |
USERNAME VARCHAR2(30) User ID of the user performing the operation |
34 |
SQL_ADDRESS RAW(4 | 8) Used with the value of the SQL_HASH_VALUE column to identify the SQL statement as |
35 |
sociated with the operation |
36 |
SQL_HASH_VALUE NUMBER Used with the value of the SQL_ADDRESS column to identify the SQL statement assoc |
37 |
iated with the operation |
38 |
SQL_ID VARCHAR2(13) SQL identifier of the SQL statement associated with the long operation, if any |
39 |
SQL_PLAN_HASH_VALUE NUMBER SQL plan hash value; NULL if SQL_ID is NULL |
40 |
SQL_EXEC_START DATE Time when the execution of the SQL started; NULL if SQL_ID is NULL |
41 |
SQL_EXEC_ID NUMBER SQL execution identifier (see V$SQL_MONITOR) |
42 |
SQL_PLAN_LINE_ID NUMBER SQL plan line ID corresponding to the long operation; NULL if the long operation |
43 |
is not associated with a line of the execution plan |
44 |
SQL_PLAN_OPERATION VARCHAR2(30) Plan operation name; NULL if SQL_PLAN_LINE_ID is NULL |
45 |
SQL_PLAN_OPTIONS VARCHAR2(30) Plan operation options; NULL if SQL_PLAN_LINE_ID is NULL |
46 |
QCSID NUMBER Session identifier of the parallel coordinator |
########sample V$SQL_MONITOR
https://www.cnblogs.com/andy6/p/7507195.html
https://docs.oracle.com/cd/B28359_01/server.111/b28320/dynviews_3048.htm#REFRN30479
https://oracle-base.com/articles/11g/real-time-sql-monitoring-11gr1
具体监控语句如下：
###for V$SESSION_LONGOPS
select * from (
select
lops.SQL_ID||' elapsed time '||lops.ELAPSED_SECONDS
from V$SESSION_LONGOPS lops
where lops.SQL_ID is not null and username <> 'SYS'
and ELAPSED_SECONDS >= 60*60*4 and time_remaining>0
group by lops.SQL_ID,USERNAME, ELAPSED_SECONDS
order by ELAPSED_SECONDS desc
) where rownum <= 5
##for gv$sql_monito
select '- sql_id= ->',sql_id,'- username= ->',username,
'- sql_exec_start= ->',to_char(sql_exec_start,'yyyy-mm-dd hh24:mi:ss') sql_exec_start,
'- LAST_REFRESH_TIME= ->',to_char(LAST_REFRESH_TIME,'yyyy-mm-dd hh24:mi:ss') LAST_REFRESH_TIME,
'- FIRST_REFRESH_TIME= ->',to_char(FIRST_REFRESH_TIME,'yyyy-mm-dd hh24:mi:ss') FIRST_REFRESH_TIME,
'- STATUS= ->',STATUS,'- sid= ->',SID,'- PROGRAM= ->',PROGRAM,'- USERNAME= ->',USERNAME
,'- Duration_seconds= ->',(LAST_REFRESH_TIME-FIRST_REFRESH_TIME)* 24 * 60 * 60 as Duration_seconds
from gv$sql_monitor
where username not in ('SYS','SYSTEM')
and status='EXECUTING'
and (LAST_REFRESH_TIME-FIRST_REFRESH_TIME)* 24 * 60 * 60 > 7200
11g中引入了新的动态性能视图V$SQL_MONITOR，该视图用以显示Oracle监视的SQL语句信息。SQL监视会对那些并行执行或者消耗5秒以上cpu时间或I/O时间的SQL语句自动启动，同时在V$SQL_MONITOR视图中产生一条记录。当SQL语句正在执行，V$SQL_MONITOR视图中的统计信息将被实时刷新，频率为每秒1次。SQL语句执行完成后，监视信息将不会被立即删除，Oracle会保证相关记录保存一分钟(由参数_sqlmon_recycle_time所控制，默认为60s)，最终这些记录都会被删除并被重用。这一新的SQL性能监视特性仅在CONTROL_MANAGEMENT_PACK_ACCESS为DIAGNOSTIC+TUNING和STATISTICS_LEVEL为ALL|TYPICAL时被启用。
v$sql_monitor视图包含当前正在运行的SQL语句，以及最近运行的SQL语句。
使用v$sql_monitor视图中所监控的SQL语句时需在满足以下条件：
1） 自动监控任何并行语句
2） 如果一个SQL语句消耗了超过5秒的CPU或I/O时间，则会自动监控
3） 监控任何在语句级启用监控的SQL语句（使用monitor或no_monitor）
提示：结合v$sql_monitor视图与v$sql_plan_monitor视图可以进一步查询SQL的执行计划等信息。联合一些其他视图，如v$active_session_history、v$session、v$session_longops、v$sql、v$sql_plan等，可以获得关于SQL的更多信息。
注意：为了进行SQL监控，初始化参数STATISTICS_LEVEL必须设置为TYPICAL或ALL，CONTROL_MANAGEMENT_PACK_ACCESS必须设置为DIAGNOSTIC+TUNING。
SQL> show parameter STATISTICS_LEVE
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
statistics_level string TYPICAL
SQL> show parameter CONTROL_MANAGEMENT_PACK_ACCESS
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_management_pack_access string DIAGNOSTIC+TUNING
1、 如查看数据库中消耗CPU资源排名前10位的查询：
select * from (
select sql_id,username,to_char(sql_exec_start,'yyyy-mm-dd hh24:mi:ss') sql_exec_start,
sql_exec_id,sum(buffer_gets) buffer_gets,
sum(disk_reads) disk_reads,round(sum(cpu_time/1000000),1) cpu_secs
from v$sql_monitor
where username not in ('SYS','SYSTEM')
group by sql_id,username,sql_exec_start,sql_exec_id
order by 7 desc)
where rownum<=10;
SQL_ID USERNAME SQL_EXEC_START SQL_EXEC_ID BUFFER_GETS DISK_READS CPU_SECS
------------- ------------------------------ ------------------- ----------- ----------- ---------- ----------
8p8ann3c68vxc SCOTT 2016-11-24 09:50:20 16777216 0 0 37.1
2、监控指定的SQL语句：
2.1、 Hint提示监控指定的SQL语句
select /*+ monitor */e.empno,e.ename,e.sal,d.dname from scott.emp e,scott.dept d where e.deptno=d.deptno;
2.2、v$sql_monitor视图中查看被监控的SQL语句消耗的资源信息：
select sql_id,username,to_char(sql_exec_start,'yyyy-mm-dd hh24:mi:ss') sql_exec_start,
sql_exec_id,sum(buffer_gets) buffer_gets,
sum(disk_reads)disk_reads,round(sum(cpu_time/1000000),1) cpu_secs
from v$sql_monitor
where sql_text like '%monitor%'
group by sql_id,username,sql_exec_start,sql_exec_id;
2.3、 然后可以使用DBMS_SQLTUNE包来查看SQL语句生成的监控信息（如执行计划等）：
SQL>
set long 10000000
set longchunksize 10000000
set linesize 200
select dbms_sqltune.report_sql_monitor from dual;