Monitor large operations with V $ session_longops
Author: Lunar
We can use the V $ SESSION_LONGOPS view to monitor any operational operations (DDL and DML). Before using it, you must meet two conditions:
1. Set Timed_statistics or SQL_TRACE,
2. Because this feature can only be applied to cost-based optimizer, statistics must be present
The same functionality can also be done using DBMS_Application_info.set_session_longops provided by Oracle 9i.
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 completion
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 color associated with the Operation of THE OFECN
SQL_HASH_VALUE
Numer
Used with the value of the sql_address column to id11 the sql statement associated with the operation
QCSID
Number
Session Identifier of The Parallel Coordinator
The following script will display a status information indicating that the DDL operation has been used for a long run time.
SELECT SID, MESSAGE
From v $ session_longops
WHERE SID = & SID
ORDER by start_time;
Example 1 - Surveillance Creation Large Index (DDL)
Microsoft Windows 2000 [Version 5.00.2195]
(C) All rights reserved 1985-2000 Microsoft Corp.
C: /> SQLPLUS LUNAR / LUNAR @ Lunarsql * Plus: Release 9.2.0.1.0 - Production on Tuesday 15 16:32:25 2004
CopyRight (C) 1982, 2002, Oracle Corporation. All Rights Reserved.
Connected to:
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
------------
9
SQL> SET TIME ON
17:16:51 SQL> CREATE INDEX IDX_T ON T (Object_ID);
Index has been created.
Time: 00: 03: 08.00
17:20:19 SQL>
In another session:
SQL> Conn Lunar / Lunar @ Lunar
connected.
SQL> Analyze Table TiStimate Statistics Sample 1 Percent;
The table has been analyzed.
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 block done
9 Sort Output:: 9482 out of 9482 block done
Time: 00: 00: 00.00
SQL>
Example 2 - Monitor full mete scan
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 is "Lunar"
SQL>
SQL> SELECT AVG_SPACE from User_Tables
2 where Table_name = 't';
AVG_SPACE
------------
867 Description has statistics
SQL> Show parameter timed_stat
Name Type Value
----------------------------------- --- -----------
TIMED_STATISTICS BOOLEAN TRUESQL> SELECT * FROM T;
3209,728 is selected.
Time: 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 Get
250492 CONSISTENT GETS
39165 Physical READS
0 redo size
187470467 BYTES SENT VIA SQL * NET to Client
2354294 BYtes Received Via SQL * NET from Clom Clism
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) All rights reserved 1985-2000 Microsoft Corp.
C: /> SQLPLUS "/ @ lunar as sysdba"
SQL * Plus: Release 9.2.0.1.0 - Production on Tuesday, Tuesday 15 17:57:04 2004
CopyRight (C) 1982, 2002, Oracle Corporation. All Rights Reserved.
Connected to:
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 block done
9 Sort Output:: 9482 out of 9482 block done
9 Table Scan: Lunar.t: 39173 Out of 39173 Blocks Done9 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
9 lines have been 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 2.7039264289179
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 1009 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 1009 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 35714 Rows SELECTED
SQL>
