PLSQL_查询SQL的执行次数和频率（案例）

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一、摘要

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

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, EXECUTIONSFROM V$SQLAREAWHERE 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 DESCORDER BY BEGIN_INTERVAL_TIME DESC-- order by TOTAL_WAIT_SECS desc；

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