【Oracle Database 12c新特性】SYS_AUTO_SPM_EVOLVE_TASK 自动作业

Oracle Database 12c中引入了一个新的自动系统作业,即SYS_AUTO_SPM_EVOLVE_TASK。 该作业将在每天的自动维护作业窗口中自动执行。 SYS_AUTO_SPM_EVOLVE_TASK负责检索和排序SPM中未被接受的执行计划non-accepted plan以便verification。 当此执行计划经过verified,过该计划满足性能阀值则将被自动接受accepted 。因此,当优化器将一个non-accepted的执行计划加入到SQL statement plan history中,在很多情况下若该计划确实是更好的,则会在第二天被接受并可以使用。

 

注意该自动task存在时间上的限制为一个小时(默认TIME_LIMIT=3600s),因此可能造成部分计划未被verified。 在此种场景下,下一个维护窗口该task执行时将处理剩余的执行计划。

 

 

SYS_AUTO_SPM_EVOLVE_TASK

  1  SELECT parameter_name, parameter_value
  2  FROM   dba_advisor_parameters
  3* WHERE  task_name = 'SYS_AUTO_SPM_EVOLVE_TASK'
SQL> /

PARAMETER_NAME                 PARAMETER_VALUE
------------------------------ ----------------------------------------
DAYS_TO_EXPIRE                 UNLIMITED
END_SNAPSHOT                   UNUSED
END_TIME                       UNUSED
INSTANCE                       UNUSED
JOURNALING                     INFORMATION
MODE                           COMPREHENSIVE
START_SNAPSHOT                 UNUSED
START_TIME                     UNUSED
TARGET_OBJECTS                 1
TIME_LIMIT                     3600
DEFAULT_EXECUTION_TYPE         SPM EVOLVE
CON_DBID_MAPPING               UNUSED
ORA_EM_PARAM1                  UNUSED
ORA_EM_PARAM2                  UNUSED
ORA_EM_PARAM3                  UNUSED
ORA_EM_PARAM4                  UNUSED
ORA_EM_PARAM5                  UNUSED
ORA_EM_PARAM6                  UNUSED
ORA_EM_PARAM7                  UNUSED
ORA_EM_PARAM8                  UNUSED
ORA_EM_PARAM9                  UNUSED
ORA_EM_PARAM10                 UNUSED
EXECUTION_DAYS_TO_EXPIRE       30
SQLSET_NAME                    UNUSED
SQLSET_OWNER                   UNUSED
ACCEPT_PLANS                   TRUE
_SPM_VERIFY                    TRUE
APPLY_CAPTURED_COMPILENV       UNUSED
LOCAL_TIME_LIMIT               UNUSED

已选择 29 行。

 select execution_name,status,execution_start,execution_end from dba_advisor_executions where task_name='SYS_AUTO_SPM_EVOLVE_TASK';


  --     time_limit  (IN) - Time limit in number of minutes.  The time limit
  --                        is global and it is used in the following manner.
  --                        The time limit for first non-accepted plan is equal
  --                        to the input value. The time limit for the second
  --                        non-accepted plan is equal to (input value - time
  --                        spent in first plan verification) and so on. The
  --                        default DBMS_SPM.AUTO_LIMIT means let the system
  --                        choose an appropriate time limit based on the
  --                        number of plan verifications required to be done.
  --                        The value DBMS_SPM.NO_LIMIT means no time limit.
  
  
  
DECLARE
   job                   BINARY_INTEGER := :job;
   next_date             TIMESTAMP WITH TIME ZONE := :mydate;
   broken                BOOLEAN := FALSE;
   job_name              VARCHAR2 (30) := :job_name;
   job_subname           VARCHAR2 (30) := :job_subname;
   job_owner             VARCHAR2 (30) := :job_owner;
   job_start             TIMESTAMP WITH TIME ZONE := :job_start;
   job_scheduled_start   TIMESTAMP WITH TIME ZONE := :job_scheduled_start;
   window_start          TIMESTAMP WITH TIME ZONE := :window_start;
   window_end            TIMESTAMP WITH TIME ZONE := :window_end;
   chain_id              VARCHAR2 (14) := :chainid;
   credential_owner      VARCHAR2 (30) := :credown;
   credential_name       VARCHAR2 (30) := :crednam;
   destination_owner     VARCHAR2 (30) := :destown;
   destination_name      VARCHAR2 (30) := :destnam;
   job_dest_id           VARCHAR2 (14) := :jdestid;
   log_id                NUMBER := :log_id;
BEGIN
   DECLARE
      ename   VARCHAR2 (30);
   BEGIN
      ename := DBMS_SQLTUNE.execute_tuning_task ('SYS_AUTO_SQL_TUNING_TASK');
      ename := DBMS_SPM.execute_evolve_task ('SYS_AUTO_SPM_EVOLVE_TASK');
   END;

   :mydate := next_date;

   IF broken
   THEN
      :b := 1;
   ELSE
      :b := 0;
   END IF;
END;




/* Formatted on 2013/8/4 10:48:19 (QP5 v5.163.1008.3004) */
  SELECT pl.signature,
         pl.category,
         pl.name,
         pl.plan_id,
         DECODE (BITAND (pl.flags, :1), 0, :2, :3) flags,
         pl.sql_handle,
         pl.sql_text,
         pl.comp_data,
         pl.optimizer_env,
         pl.bind_data,
         pl.parsing_schema_name,
         pl.creator,
         (CASE                                  /* plan is already accepted */
             WHEN (BITAND (pl.flags, :4) <> 0)
             THEN
                :5                       /* plan has recently been verified */
             WHEN (pl.is_auto IS NOT NULL
                   AND pl.last_verified >
                          SYSTIMESTAMP
                          - :6)
             THEN
                :7    /* plan's SQL statement hasn't been recently executed */
             WHEN (pl.is_auto
                      IS NOT NULL
                   AND pl.last_verified
                          IS NOT NULL
                   AND pl.sql_last_executed <
                          SYSTIMESTAMP
                          - :8)
             THEN
                :9
             ELSE
                :10
          END)
            pruned
    FROM (SELECT so.signature,
                 so.category,
                 so.name,
                 so.plan_id,
                 so.flags,
                 st.sql_handle,
                 st.sql_text,
                 (DECODE (
                     BITAND (so.flags, 128),
                     128, (SELECT EXTRACT (XMLTYPE (pl.other_xml),
                                           '/*/outline_data').getClobVal ()
                             FROM sys.sqlobj$plan pl
                            WHERE     pl.signature = so.signature
                                  AND pl.category = so.category
                                  AND pl.obj_type = so.obj_type
                                  AND pl.plan_id = so.plan_id
                                  AND pl.other_xml IS NOT NULL),
                     (SELECT sod.comp_data
                        FROM sys.sqlobj$data sod
                       WHERE     sod.signature = so.signature
                             AND sod.category = so.category
                             AND sod.obj_type = so.obj_type
                             AND sod.plan_id = so.plan_id)))
                    comp_data,
                 sox.optimizer_env,
                 sox.bind_data,
                 sox.parsing_schema_name,
                 sox.creator,
                 sox.last_verified,
                 sox.optimizer_cost,
                 sox.created,
                 :11 is_auto,
                 (SELECT MAX (last_executed)
                    FROM sys.sqlobj$ ob
                   WHERE     ob.signature = so.signature
                         AND ob.obj_type = so.obj_type
                         AND ob.category = so.category)
                    sql_last_executed
            FROM sys.sqlobj$ so, sys.sqlobj$auxdata sox, sys.sql$text st
           WHERE (:12 IS NULL
                  OR so.name IN (SELECT EXTRACTVALUE (VALUE (p), '/plan') pname
                                   FROM TABLE (
                                           XMLSEQUENCE (
                                              EXTRACT (XMLTYPE (:13),
                                                       '/plan_list/*'))) p))
                 AND (:14 IS NOT NULL
                      OR (BITAND (so.flags, :15) <> 0
                          AND BITAND (so.flags, :16) = 0))
                 AND so.obj_type = :17
                 AND so.signature = sox.signature
                 AND so.category = sox.category
                 AND so.obj_type = sox.obj_type
                 AND so.plan_id = sox.plan_id
                 AND so.signature = st.signature) pl
ORDER BY DECODE (:18, 0, NULL, pl.name),
         pl.last_verified NULLS FIRST,
         pl.sql_last_executed DESC NULLS LAST,
         pl.optimizer_cost,
         pl.created,
         pl.name