ORACLE數(shù)據(jù)庫查看執(zhí)行計劃的方法

SQL>EXPLAIN PLAN FOR
SELECT * FROM SCOTT.EMP; --要解析的SQL腳本
SQL>SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY);

SQL>SET TIMING ON 　　　　　　　　　　　　--控制顯示執(zhí)行時間統(tǒng)計數(shù)據(jù)
SQL>SET AUTOTRACE ON EXPLAIN 　　　 　　--這樣設(shè)置包含執(zhí)行計劃、腳本數(shù)據(jù)輸出，沒有統(tǒng)計信息
SQL>執(zhí)行需要查看執(zhí)行計劃的SQL語句
SQL>SET AUTOTRACE OFF 　　　　　　　　　 --不生成AUTOTRACE報告，這是缺省模式
SQL> SET AUTOTRACE ON 　　　　　　　　　 --這樣設(shè)置包含執(zhí)行計劃、統(tǒng)計信息、以及腳本數(shù)據(jù)輸出
SQL>執(zhí)行需要查看執(zhí)行計劃的SQL語句
SQL>SET AUTOTRACE OFF
SQL> SET AUTOTRACE TRACEONLY 　　　　　--這樣設(shè)置會有執(zhí)行計劃、統(tǒng)計信息，不會有腳本數(shù)據(jù)輸出
SQL>執(zhí)行需要查看執(zhí)行計劃的SQL語句
SQL>SET AUTOTRACE TRACEONLY STAT --這樣設(shè)置只包含有統(tǒng)計信息
SQL>執(zhí)行需要查看執(zhí)行計劃的SQL語句

SQL> ALTER SESSION SET SQL_TRACE=TRUE;
SQL> SELECT * FROM SCOTT.EMP;
SQL> ALTER SESSION SET SQL_TRACE =FALSE;

SELECT T.VALUE || '/' || LOWER(RTRIM(I.INSTANCE, CHR(0))) || '_ora_' ||
P.SPID || '.trc' TRACE_FILE_NAME
FROM
( SELECT P.SPID
FROM V$MYSTAT M, V$SESSION S, V$PROCESS P
WHERE M.STATISTIC# =1
AND S.SID = M.SID
AND P.ADDR = S.PADDR
) P,
( SELECT T.INSTANCE
FROM V$THREAD T, V$PARAMETER V
WHERE V.NAME ='thread'
AND (V.VALUE = 0 OR T.THREAD# = TO_NUMBER(V.VALUE))
) I,
(SELECT VALUE FROM V$PARAMETER WHERE NAME='user_dump_dest') T

TKPROF 選項(xiàng)
選項(xiàng) 說明
TRACEFILE 跟蹤輸出文件的名稱
OUTPUTFILE 已設(shè)置格式的文件的名稱
SORT=option 語句的排序順序
PRINT=n 打印前 n 個語句
EXPLAIN=user/password 以指定的用戶名運(yùn)行 EXPLAIN PLAN
INSERT=filename 生成 INSERT 語句
SYS=NO 忽略作為用戶 sys 運(yùn)行的遞歸 SQL 語句
AGGREGATE=[Y|N] 如果指定 AGGREGATE = NO TKPROF 不聚集相同
SQL 文本的多個用戶
RECORD=filename 記錄在跟蹤文件中發(fā)現(xiàn)的語句
TABLE=schema.tablename 將執(zhí)行計劃放入指定的表而不是缺省的PLAN_TABLE

可以在操作系統(tǒng)中鍵入 tkprof 以獲得所有可用選項(xiàng)和輸出的列表
注 排序選項(xiàng)有

排序 選項(xiàng)說明
prscnt execnt fchcnt 調(diào)用分析執(zhí)行提取的次數(shù)
prscpu execpu fchcpu 分析執(zhí)行提取所占用的 CPU 時間
prsela exela fchela 分析執(zhí)行提取所占用的時間
prsdsk exedsk fchdsk 分析執(zhí)行提取期間的磁盤讀取次數(shù)
prsqry exeqry fchqry 分析執(zhí)行提取期間用于持續(xù)讀取的緩沖區(qū)數(shù)
prscu execu fchcu 分析執(zhí)行提取期間用于當(dāng)前讀取的緩沖區(qū)數(shù)
prsmis exemis 分析執(zhí)行期間庫高速緩存未命中的次數(shù)
exerow fchrow 分析執(zhí)行期間處理的行數(shù)
userid 分析游標(biāo)的用戶的用戶 ID

TKPROF 統(tǒng)計數(shù)據(jù)
Count: 執(zhí)行調(diào)用數(shù)
CPU: CPU 的使用秒數(shù)
Elapsed: 總共用去的時間
Disk: 物理讀取次數(shù)
Query: 持續(xù)讀取的邏輯讀取數(shù)
Current: 當(dāng)前模式下的邏輯讀取數(shù)
Rows: 已處理行數(shù)
TKPROF 統(tǒng)計信息
統(tǒng)計 含義
Count 分析或執(zhí)行語句的次數(shù)以及為語句發(fā)出的提取調(diào)用數(shù)
CPU 每個階段的處理時間以秒為單位如果在共享池中找到該語句對于分析階段為 0
Elapsed 占用時間以秒為單位通常不是非常有用因?yàn)槠渌M(jìn)程影響占用時間
Disk 從數(shù)據(jù)庫文件讀取的物理數(shù)據(jù)塊如果該數(shù)據(jù)被緩沖則該統(tǒng)計可能很低
Query 為持續(xù)讀取檢索的邏輯緩沖區(qū)通常用于 SELECT 語句
Current 在當(dāng)前模式下檢索的邏輯緩沖區(qū)通常用于 DML 語句
Rows 外部語句所處理的行對于 SELECT 語句在提取階段顯示它對于 DML 語句在執(zhí)行階段顯示它

Query 和Current 的總和為所訪問的邏輯緩沖區(qū)的總數(shù)

TKPROF: Release 10.2.0.1.0 - Production on 星期三 5月 23 16:56:41 2012
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Trace file: D:\ORACLE\PRODUCT\10.2.0\DB_1\RDBMS\TRACE/wgods_ora_3940.trc
Sort options: default
********************************************************************************
count = number of times OCI procedure was executed
cpu = cpu time in seconds executing
elapsed = elapsed time in seconds executing
disk = number of physical reads of buffers from disk
query = number of buffers gotten for consistent read
current = number of buffers gotten in current mode (usually for update)
rows = number of rows processed by the fetch or execute call
********************************************************************************
ALTER SESSION SET SQL_TRACE = TRUE
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 1 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
Misses in library cache during execute: 1
Optimizer mode: CHOOSE
Parsing user id: 89 (ETL)
********************************************************************************
begin :id := sys.dbms_transaction.local_transaction_id; end;
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 2 0.00 0.00 0 0 0 0
Execute 2 0.00 0.00 0 0 0 2
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 4 0.00 0.00 0 0 0 2
Misses in library cache during parse: 0
Optimizer mode: CHOOSE
Parsing user id: 89 (ETL)
********************************************************************************
SELECT *
FROM
SCOTT.EMP
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 2 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 1 0.00 0.00 0 7 0 14
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 4 0.00 0.00 0 7 0 14
Misses in library cache during parse: 1
Optimizer mode: CHOOSE
Parsing user id: 89 (ETL)
Rows Execution Plan
------- ---------------------------------------------------
SELECT STATEMENT MODE: CHOOSE
TABLE ACCESS MODE: ANALYZED (FULL) OF 'EMP' (TABLE)
********************************************************************************
ALTER SESSION SET SQL_TRACE = FALSE
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0 0 0
Execute 1 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 2 0.00 0.00 0 0 0 0
Misses in library cache during parse: 1
Optimizer mode: CHOOSE
Parsing user id: 89 (ETL)
********************************************************************************
OVERALL TOTALS FOR ALL NON-RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 5 0.00 0.00 0 0 0 0
Execute 5 0.00 0.00 0 0 0 2
Fetch 1 0.00 0.00 0 7 0 14
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 11 0.00 0.00 0 7 0 16
Misses in library cache during parse: 2
Misses in library cache during execute: 1
OVERALL TOTALS FOR ALL RECURSIVE STATEMENTS
call count cpu elapsed disk query current rows
------- ------ -------- ---------- ---------- ---------- ---------- ----------
Parse 0 0.00 0.00 0 0 0 0
Execute 0 0.00 0.00 0 0 0 0
Fetch 0 0.00 0.00 0 0 0 0
------- ------ -------- ---------- ---------- ---------- ---------- ----------
total 0 0.00 0.00 0 0 0 0
Misses in library cache during parse: 0
user SQL statements in session.
internal SQL statements in session.
SQL statements in session.
statement EXPLAINed in this session.
********************************************************************************
Trace file: D:\ORACLE\PRODUCT\10.2.0\DB_1\RDBMS\TRACE/wgods_ora_3940.trc
Trace file compatibility: 10.01.00
Sort options: default
session in tracefile.
user SQL statements in trace file.
internal SQL statements in trace file.
SQL statements in trace file.
unique SQL statements in trace file.
SQL statements EXPLAINed using schema:
ETL.prof$plan_table
Default table was used.
Table was created.
Table was dropped.
lines in trace file.
elapsed seconds in trace file.

SELECT SID, SERIAL#, USERNAME FROM V$SESSION WHERE USERNAME = 'ETL'
EXEC DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(61,76,TRUE);
EXEC DBMS_SYSTEM.SET_SQL_TRACE_IN_SESSION(61,76,FALSE);

ALTER SESSION SET TRACEFILE_IDENTIFIER = 10046;
ALTER SESSION SET EVENTS='10046 trace name context forever, level 8';
SELECT * FROM SCOTT.EMP;
ALTER SESSION SET EVENTS ='10046 trace name context off';
然后你可以用腳本查看追蹤文件的位置
SELECT T.VALUE || '/' || LOWER(RTRIM(I.INSTANCE, CHR(0))) || '_ora_' ||
P.SPID || '.trc' TRACE_FILE_NAME
FROM
( SELECT P.SPID
FROM V$MYSTAT M, V$SESSION S, V$PROCESS P
WHERE M.STATISTIC# =1
AND S.SID = M.SID
AND P.ADDR = S.PADDR
) P,
( SELECT T.INSTANCE
FROM V$THREAD T, V$PARAMETER V
WHERE V.NAME ='thread'
AND (V.VALUE = 0 OR T.THREAD# = TO_NUMBER(V.VALUE))
) I,
(SELECT VALUE FROM V$PARAMETER WHERE NAME='user_dump_dest') T
查詢結(jié)果為wgods_ora_28279.trc文件， 但是去相應(yīng)目錄卻沒有找到對應(yīng)的追蹤文件，而是如下trace文件：wgods_ora_28279_10046.trc

SELECT * FROM V$SQL_PLAN
SELECT * FROM V$RSRC_PLAN_CPU_MTH
SELECT * FROM V$SQL_PLAN_STATISTICS
SELECT * FROM V$SQL_PLAN_STATISTICS_ALL
SELECT * FROM V$SQLAREA_PLAN_HASH
SELECT * FROM V$RSRC_PLAN_HISTORY