用v$session_longops监视大型操作

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用v$session_longops监视大型操作

作者：Lunar

我们可以使用v$session_longops视图用于监视任何运行时间很长的操作（DDL和DML）。，使用它之前必须满足两个条件：

1. 设置TIMED_STATISTICS 或者SQL_TRACE，

2. 因为这个功能只能应用于基于成本的优化器，所以必须存在统计数据

与之相同的功能也可以使用Oracle 9i提供的DBMS_APPLICATION_INFO.SET_SESSION_LONGOPS来完成。

Column

Datatype

Description

SID

NUMBER

Session identifier

SERIAL#

NUMBER

Session serial number

OPNAME

VARCHAR2(64)

Brief description of the operation

TARGET

VARCHAR2(64)

The object on which the operation is carried out

TARGET_DESC

VARCHAR2(32)

Description of the target

SOFAR

NUMBER

The units of work done so far

TOTALWORK

NUMBER

The total units of work

UNITS

VARCHAR2(32)

The units of measurement

START_TIME

DATE

The starting time of operation

LAST_UPDATE_TIME

DATE

Time when statistics last updated

TIME_REMAINING

NUMBER

Estimate (in seconds) of time remaining for the operation to complete

ELAPSED_SECONDS

NUMBER

The number of elapsed seconds from the start of operations

CONTEXT

NUMBER

Context

MESSAGE

VARCHAR2(512)

Statistics summary message

USERNAME

VARCHAR2(30)

User ID of the user performing the operation

SQL_ADDRESS

RAW(4)

Used with the value of the SQL_HASH_VALUE column to identify the SQL statement associated with the operation

SQL_HASH_VALUE

NUMER

Used with the value of the SQL_ADDRESS column to identify the SQL statement associated with the operation

QCSID

NUMBER

Session identifier of the parallel coordinator

下面的脚本将显示一个状态信息，说明了运行时间很长的DDL操作已经使用的时间。

Select sid, message

From v$session_longops

Where sid = &sid

order by start_time;

实例1——监视创建大索引（DDL）

Microsoft Windows 2000 [Version 5.00.2195]

C:/>sqlplus lunar/lunar@lunar

SQL*Plus: Release 9.2.0.1.0 - Production on 星期二 6月 15 16:32:25 2004

连接到:

Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production

With the OLAP and Oracle Data Mining options

JServer Release 9.2.0.1.0 - Production

SQL> select distinct sid from v$mystat;

SID

----------

SQL> set time on

17:16:51 SQL> create index idx_t on t(OBJECT_ID);

索引已创建。

已用时间: 00: 03: 08.00

17:20:19 SQL>

在另一个session中：

SQL> conn lunar/lunar@lunar

已连接。

SQL> analyze table t ESTIMATE STATISTICS sample 1 PERCENT;

表已分析。

SQL> set linesize 1000

SQL> column message format a70

SQL> Select sid, message

2 From v$session_longops

3 Where sid = 9

4 order by start_time

5 /

SID MESSAGE

---------- --------------------------------------------------------

9 Table Scan: LUNAR.T: 19537 out of 19537 Blocks done

9 SQL Execution: : 1881 out of 1881 units done

9 Table Scan: LUNAR.T: 39173 out of 39173 Blocks done

9 Sort/Merge: : 9976 out of 9976 Blocks done

9 Sort Output: : 9482 out of 9482 Blocks done

已用时间: 00: 00: 00.00

SQL>

实例2——监视全表扫描

SELECT sid, serial#, opname,

TO_CHAR(start_time,'HH24:MI:SS') AS start_time,

(sofar/totalwork)*100 AS PERCENT_COMPLETE,

ELAPSED_SECONDS

FROM v$session_longops;

SQL> SHOW USER

USER 为"LUNAR"

SQL>

SQL> select avg_space from user_tables

2 where table_name='T';

AVG_SPACE

----------

867 说明有统计数据

SQL> show parameter timed_stat

NAME TYPE VALUE

------------------------------------ ----------- --------------

timed_statistics boolean TRUE

SQL> select * from t;

已选择3209728行。

已用时间: 00: 05: 38.06

Execution Plan

----------------------------------------------------------

0 SELECT STATEMENT Optimizer=CHOOSE (Cost=1881 Card=1605276 By

tes=120395700)

1 0 TABLE ACCESS (FULL) OF 'T' (Cost=1881 Card=1605276 Bytes=1

20395700)

Statistics

----------------------------------------------------------

0 recursive calls

0 db block gets

250492 consistent gets

39165 physical reads

0 redo size

187470467 bytes sent via SQL*Net to client

2354294 bytes received via SQL*Net from client

213983 SQL*Net roundtrips to/from client

0 sorts (memory)

0 sorts (disk)

3209728 rows processed

SQL>

Microsoft Windows 2000 [Version 5.00.2195]

C:/>sqlplus "/@lunar as sysdba"

SQL*Plus: Release 9.2.0.1.0 - Production on 星期二 6月 15 17:57:04 2004

连接到:

Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production

With the OLAP and Oracle Data Mining options

JServer Release 9.2.0.1.0 - Production

SQL> set linesize 1000

SQL> column message format a70

SQL> Select sid, message

2 From v$session_longops

3 Where sid = 9

4 order by start_time

5 /

SID MESSAGE

---------- ----------------------------------------------------------------------

9 Table Scan: LUNAR.T: 19537 out of 19537 Blocks done

9 SQL Execution: : 1881 out of 1881 units done

9 Table Scan: LUNAR.T: 39173 out of 39173 Blocks done

9 Sort/Merge: : 9976 out of 9976 Blocks done

9 Sort Output: : 9482 out of 9482 Blocks done

9 Table Scan: LUNAR.T: 39173 out of 39173 Blocks done

9 SQL Execution: : 1881 out of 1881 units done

9 Table Scan: LUNAR.T: 39173 out of 39173 Blocks done

9 SQL Execution: : 1881 out of 1881 units done

已选择9行。

SQL> /

SID SERIAL# OPNAME START_TIME PERCENT_COMPLETE

---------- ---------- -------------------------- ---------- ----------------

10 86 Import Schema Statistics 17:03:44 100

10 86 Delete Schema Statistics 17:04:02 100

9 167 Table Scan 17:05:21 100

9 167 SQL Execution 17:05:21 100

9 167 Table Scan 17:17:11 100

9 167 Sort/Merge 17:18:10 100

9 167 Sort Output 17:18:56 100

9 167 Table Scan 17:28:19 100

9 167 SQL Execution 17:28:19 100

9 167 Table Scan 17:28:52 100

9 167 SQL Execution 17:28:52 100

9 182 Table Scan 17:59:14 100

9 182 Table Scan 18:22:02 100

9 182 Table Scan 18:24:17 2.70339264289179

14 rows selected

SQL> /

SID SERIAL# OPNAME START_TIME PERCENT_COMPLETE

---------- ---------- -------------------------- ---------- ----------------

10 86 Import Schema Statistics 17:03:44 100

10 86 Delete Schema Statistics 17:04:02 100

9 167 Table Scan 17:05:21 100

9 167 SQL Execution 17:05:21 100

9 167 Table Scan 17:17:11 100

9 167 Sort/Merge 17:18:10 100

9 167 Sort Output 17:18:56 100

9 167 Table Scan 17:28:19 100

9 167 SQL Execution 17:28:19 100

9 167 Table Scan 17:28:52 100

9 167 SQL Execution 17:28:52 100

9 182 Table Scan 17:59:14 100

9 182 Table Scan 18:22:02 100

9 182 Table Scan 18:24:17 44.0354325683506

14 rows selected

SQL> /

SID SERIAL# OPNAME START_TIME PERCENT_COMPLETE

---------- ---------- -------------------------- ---------- ----------------

10 86 Import Schema Statistics 17:03:44 100

10 86 Delete Schema Statistics 17:04:02 100

9 167 Table Scan 17:05:21 100

9 167 SQL Execution 17:05:21 100

9 167 Table Scan 17:17:11 100

9 167 Sort/Merge 17:18:10 100

9 167 Sort Output 17:18:56 100

9 167 Table Scan 17:28:19 100

9 167 SQL Execution 17:28:19 100

9 167 Table Scan 17:28:52 100

9 167 SQL Execution 17:28:52 100

9 182 Table Scan 17:59:14 100

9 182 Table Scan 18:22:02 100

9 182 Table Scan 18:24:17 70.1860975672019

14 rows selected

SQL> SELECT sid, serial#, opname,

2 TO_CHAR(start_time,'HH24:MI:SS') AS start_time,

3 (sofar/totalwork)*100 AS PERCENT_COMPLETE,

4 ELAPSED_SECONDS

5 FROM v$session_longops;

SID SERIAL# OPNAME START_TIME PERCENT_COMPLETE ELAPSED_SECONDS

---- ---------- ---------------------------- ---------- ---------------- ---------------

10 86 Import Schema Statistics 17:03:44 100 0

10 86 Delete Schema Statistics 17:04:02 100 1

9 167 Table Scan 17:05:21 100 266

9 167 SQL Execution 17:05:21 100 266

9 167 Table Scan 17:17:11 100 59

9 167 Sort/Merge 17:18:10 100 46

9 167 Sort Output 17:18:56 100 82

9 167 Table Scan 17:28:19 100 15

9 167 SQL Execution 17:28:19 100 15

9 167 Table Scan 17:28:52 100 19

9 167 SQL Execution 17:28:52 100 19

9 182 Table Scan 17:59:14 100 336

9 182 Table Scan 18:22:02 100 18

9 182 Table Scan 18:24:17 100 357

14 rows selected

SQL>