PLSQL_查询SQL的执行次数和频率（案例）

2014-12-25 Created By BaoXinjian

一、摘要

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在ORACLE数据库应用调优中，一个SQL的执行次数/频率也是常常需要关注的，因为某个SQL执行太频繁，要么是由于应用设计有缺陷，需要在业务逻辑上做出优化处理，要么是业务特殊性所导致。

如果执行频繁的SQL，往往容易遭遇一些并发性的问题。

那么如何查看ORACLE数据库某个SQL的执行频率/次数，潇湘隐者同学整理如下，借花献佛了 :)

 

方法1： 通过查询V$SQLAREA或V$SQL的EXECUTIONS来查看SQL的执行次数;

方法2：通过DBA_HIST_SQLSTAT关联DBA_HIST_SNAPSHOT找出某些SQL的执行次数;

方法3：AWR报告查看某个SQL的执行次数;

 

二、三种方法解析

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1. 通过查询V$SQLAREA或V$SQL的EXECUTIONS来查看SQL的执行次数

(1). 缺点

但是这个值的有效性需要结合FIRST_LOAD_TIME来判断，因为V$SQLAREA或V$SQL中不保存历史数据，

具有一定的时效性，所以如果要查询很久以前的某个SQL执行次数是办不到的。

(2). 关于V$SQLAREA 栏位介绍

FIRST_LOAD_TIME        VARCHAR2(19)       Timestamp of the parent creation time

EXECUTIONS                 NUMBER                Total number of executions, totalled over all the child cursors

(3). 如何查询

SELECT SQL_ID, SQL_TEXT,FIRST_LOAD_TIME, EXECUTIONS FROM V$SQLAREA WHERE SQL_ID = '497wh6n7hu14f'

(4). 总结

如果此时清空共享池，那么你会发现V$SQLAREA中对应的SQL的EXECUTIONS次数清零了。

如果要查看某个时间段该SQL语句执行了多少次，那么必须在这两个时间段执行上面SQL语句，两次EXECUTIONS的差值表示这段时间内SQL语句的执行次数。

EXECUTIONS是全局的，往往不能查看某个会话或用户执行了多少次。这也是其局限性之一。

 

2. 通过DBA_HIST_SQLSTAT关联DBA_HIST_SNAPSHOT找出某些SQL的执行次数。

(1). 缺点

但是部分快照如果没有捕获到有些SQL。这样也就无法通过下面SQL语句查看执行次数。

也是就说这种方法是有缺陷的。执行越频繁的语句，也越容易被SNAPSHOT抓取到.

(2). 执行语法

  SELECT M.SQL_ID, TO_CHAR (N.BEGIN_INTERVAL_TIME, 'YYYY-MM-DD') "DATETIME", SUM (M.EXECUTIONS_DELTA) EXECUTIONS FROM DBA_HIST_SQLSTAT M, DBA_HIST_SNAPSHOT N WHERE       M.SNAP_ID = N.SNAP_ID AND M.DBID = N.DBID AND M.INSTANCE_NUMBER = N.INSTANCE_NUMBER AND M.INSTANCE_NUMBER = 1

           AND TO_CHAR (N.BEGIN_INTERVAL_TIME, 'YYYY-MM-DD') = '2014-12-25'

           AND M.SQL_ID = '497wh6n7hu14f'

GROUP BY   M.SQL_ID, TO_CHAR (N.BEGIN_INTERVAL_TIME, 'YYYY-MM-DD') ORDER BY   M.SQL_ID

 

3. AWR报告查看某个SQL的执行次数，同上面一样，AWR报告也受SNAPSHOT影响。不一定捕获了你需要查询的SQL

 

4. 查看当前数据库执行次数最多的SQL，例如，查询执行最频繁的TOP 15的SQL语句。

SELECT SQL_TEXT, EXECUTIONS FROM   (SELECT SQL_TEXT, EXECUTIONS, RANK () OVER (ORDER BY EXECUTIONS DESC) EXEC_RANK FROM V$SQLAREA) WHERE   EXEC_RANK <= 15;

 

5. 查看执行SQL的历史记录信息

  SELECT DBMS_LOB.SUBSTR (sql_text, 100, 1) SQL_SHORT,

         tab1.sql_id,

         DBMS_LOB.getlength (sql_text) SQL_Len,

         ROUND (TOTAL_WAIT / 1000000, 2) TOTAL_WAIT_SECS,

         ROUND (ELAPSED_TIME_DELTA / 1000000, 2) TOTAL_TIME_SECS,

         TO_CHAR (BEGIN_INTERVAL_TIME, 'DAY', 'NLS_DATE_LANGUAGE=AMERICAN')

            Week_Day,

         BEGIN_INTERVAL_TIME,

         END_INTERVAL_TIME,

         EXEC_COUNT,

         AVG_CPU_TIME_SECS,

         AVG_ELAPSED_SECS,

         ROUND (ELAPSED_TIME_DELTA / 1000000, 0) ELAPSED_TIME_DELTA,

         ROUND (AVG_ROWS_PROCESSED, 1) AVG_ROWS_PROCESSED,

         PLAN_HASH_VALUE,

         MODULE,

         ACTION,

         PARSING_SCHEMA_NAME,

         (SELECT username

            FROM dba_users

           WHERE user_id = PARSING_USER_ID)

            PARSING_USER,

         AVG_BUFFER_GETS,

         AVG_DISK_READS,

         AVG_IOWAIT AVG_iowai_secs,

         AVG_CCWAIT AVG_ccwait_secs,

         AVG_CLWAIT AVG_clwait_secs,

         AVG_APWAIT AVG_apwait_secs,

         AVG_PX_SERVERS,

         AVG_PARSE_CALLS,

         tab1.SNAP_ID,

         tab1.INSTANCE_NUMBER,

         AVG_CELL_UNCOMPRESSED_BYTES,

         AVG_DIRECT_WRITES,

         AVG_IO_INTERCONNECT_BYTES,

         AVG_IO_OFFLOAD_ELIG_BYTES,

         AVG_IO_OFFLOAD_RETURN_BYTES,

         AVG_JAVEXEC_TIME,

         AVG_OPTIMIZED_PHYSICAL_READS,

         AVG_PLSEXEC_TIME_DELTA,

         AVG_SORTS_DELTA,

         -- BIND_DATA,    -- -- (Falta arreglar) listagg( (select * from table(dbms_sqltune.extract_binds(bind_data)), '#') WITHIN GROUP (ORDER BY 1)) Binds ,

         DBMS_LOB.SUBSTR (sql_text, 2000, 1) SQL_TEXT1,

         DBMS_LOB.SUBSTR (sql_text, 2000, 2001) SQL_TEXT2,

         DBMS_LOB.SUBSTR (sql_text, 2000, 4001) SQL_TEXT3,

         DBMS_LOB.SUBSTR (sql_text, 2000, 6001) SQL_TEXT4,

         DBMS_LOB.SUBSTR (sql_text, 2000, 8001) SQL_TEXT5,

         DBMS_LOB.SUBSTR (sql_text, 2000, 10001) SQL_TEXT6,

         DBMS_LOB.SUBSTR (sql_text, 2000, 12001) SQL_TEXT7,

         DBMS_LOB.SUBSTR (sql_text, 2000, 14001) SQL_TEXT8,

         DBMS_LOB.SUBSTR (sql_text, 2000, 16001) SQL_TEXT9,

         DBMS_LOB.SUBSTR (sql_text, 2000, 18001) SQL_TEXT10

    FROM DBA_HIST_SQLTEXT D,

         DBA_HIST_SNAPSHOT N,

         (  SELECT S.SQL_ID SQL_ID,

                   instance_number,

                   SUM (EXECUTIONS) EXEC_COUNT,

                   ROUND ( (SUM (CPU_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,

                          4)

                      AVG_CPU_TIME_SECS,

                   ROUND (

                      (SUM (ELAPSED_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,

                      4)

                      AVG_ELAPSED_SECS,

                   SUM (ELAPSED_TIME_DELTA) ELAPSED_TIME_DELTA,

                   ROUND ( (SUM (ROWS_PROCESSED_DELTA) / SUM (EXECUTIONS)), 4)

                      AVG_ROWS_PROCESSED,

                   PLAN_HASH_VALUE,

                   MODULE,

                   ACTION,

                   PARSING_SCHEMA_NAME,

                   PARSING_USER_ID,

                   ROUND (SUM (BUFFER_GETS_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_BUFFER_GETS,

                   ROUND (SUM (DISK_READS_DELTA) / SUM (EXECUTIONS), 0)

                      AVG_DISK_READS,

                   SNAP_ID,

                   ROUND ( (SUM (IOWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)

                      AVG_IOWAIT,

                   ROUND ( (SUM (CCWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)

                      AVG_CCWAIT,

                   ROUND ( (SUM (CLWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)

                      AVG_CLWAIT,

                   ROUND ( (SUM (APWAIT_DELTA) / SUM (EXECUTIONS)) / 1000000, 4)

                      AVG_APWAIT,

                   ROUND (SUM (PX_SERVERS_EXECS_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_PX_SERVERS,

                   ROUND (SUM (PARSE_CALLS_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_PARSE_CALLS,

                   ROUND (SUM (CELL_UNCOMPRESSED_BYTES_DELTA) / SUM (EXECUTIONS),

                          4)

                      AVG_CELL_UNCOMPRESSED_BYTES,

                   ROUND (SUM (DIRECT_WRITES_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_DIRECT_WRITES,

                   ROUND (SUM (IO_INTERCONNECT_BYTES_DELTA) / SUM (EXECUTIONS),

                          4)

                      AVG_IO_INTERCONNECT_BYTES,

                   ROUND (SUM (IO_OFFLOAD_ELIG_BYTES_DELTA) / SUM (EXECUTIONS),

                          4)

                      AVG_IO_OFFLOAD_ELIG_BYTES,

                   ROUND (SUM (IO_OFFLOAD_RETURN_BYTES_DELTA) / SUM (EXECUTIONS),

                          4)

                      AVG_IO_OFFLOAD_RETURN_BYTES,

                   ROUND (SUM (JAVEXEC_TIME_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_JAVEXEC_TIME,

                   ROUND (

                      SUM (OPTIMIZED_PHYSICAL_READS_DELTA) / SUM (EXECUTIONS),

                      4)

                      AVG_OPTIMIZED_PHYSICAL_READS,

                   ROUND (SUM (PLSEXEC_TIME_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_PLSEXEC_TIME_DELTA,

                   ROUND (SUM (SORTS_DELTA) / SUM (EXECUTIONS), 4)

                      AVG_SORTS_DELTA,

                   SUM (

                      IOWAIT_DELTA + CCWAIT_DELTA + CLWAIT_DELTA + APWAIT_DELTA)

                      TOTAL_WAIT,

                   MAX (BIND_DATA) BIND_DATA

              FROM (SELECT S.*,

                           DECODE (EXECUTIONs_DELTA, 0, 1, EXECUTIONS_DELTA)

                              EXECUTIONS

                      FROM DBA_HIST_SQLSTAT S) S

             WHERE 1 = 1 -- and ( PARSING_SCHEMA_NAME like 'EUS%' )  -- Filter by schema name

          GROUP BY S.SQL_ID,

                   instance_number,

                   S.SNAP_ID,

                   PLAN_HASH_VALUE,

                   MODULE,

                   ACTION,

                   PARSING_SCHEMA_NAME,

                   S.INSTANCE_NUMBER,

                   PARSING_USER_ID

            HAVING ROUND (

                      (SUM (ELAPSED_TIME_DELTA) / SUM (EXECUTIONS)) / 1000000,

                      4) >= 10                             -- Filter >= n secs

          ORDER BY 5 DESC) TAB1

   WHERE D.SQL_ID = TAB1.SQL_ID AND TAB1.snap_id = N.snap_id --   and upper(tab1.module) like '%PKG_BATCH_PROCESSES_SDM%'

         AND d.sql_id IN ('6tmcqrydfgdtc') --  AND D.SQL_ID in ( select distinct sql_id from DBA_HIST_ACTIVE_SESS_HISTORY where top_level_sql_id = '85xkhugz5kt8h'  )

                                           --  AND upper(DBMS_LOB.SUBSTR (sql_text, 100, 1)) LIKE 'INSERT%'

                                           --   AND upper(DBMS_LOB.SUBSTR (sql_text, 1000, 1)) LIKE 'SELECT%'

                                           -- AND upper(DBMS_LOB.SUBSTR (sql_text, 3000, 1)) LIKE '%INACTIVE%'

         AND BEGIN_INTERVAL_TIME > SYSDATE - 60

-- and BEGIN_INTERVAL_TIME between to_date('05/09/2013 07:50:00', 'DD/MM/YYYY hh24:mi:ss') AND    to_date('05/09/2013 16:10:00', 'DD/MM/YYYY hh24:mi:ss')

-- and  BEGIN_INTERVAL_TIME >= (SELECT  job_start_datetime - (2/24)  FROM   job_status  WHERE   job_name = 'RAVLDBSK' AND cob_date =  (SELECT  current_cob_date  FROM  eus_cob))

-- and  BEGIN_INTERVAL_TIME <= (SELECT job_end_datetime + (2/24)  FROM   job_status  WHERE   job_name = 'RAVLDBSK' AND cob_date =  (SELECT  current_cob_date  FROM  eus_cob))

--   order by AVG_ELAPSED_SECS DESC

-- order by ELAPSED_TIME_DELTA DESC

ORDER BY BEGIN_INTERVAL_TIME DESC

-- order by TOTAL_WAIT_SECS desc；

 

Thanks and Regards

部分参考：潇湘隐者 - http://www.cnblogs.com/kerrycode/p/4111746.html