Oracle 执行FORALL时的不同执行时间。。插入。。价值观

我们正在经历一个FORALL的不同执行时间。。插入。。价值观声明。我们创建了一个模拟行为的测试。运行下面的脚本将显示随机分布的0.5到7-8秒之间的执行时间

脚本在运行SQL Developer的客户端上执行，Oracle DB在同一网络上的HyperV Server VM上运行。在这个虚拟机上，分配的内存和硬盘大小看起来足够了

不同执行时间的原因可能是什么？我们有什么可能稳定和最小化执行时间

编辑：相关性能仅为FORALL的时间。。INSERT语句需要-在脚本中使用DBMS.PUT_行命令明确测量。创建测试数据的性能与我的问题无关

以下是测试脚本：

DECLARE
  SUBTYPE t_logmsg_rec IS logmsg%ROWTYPE;
  TYPE t_logmsg_list IS TABLE OF t_logmsg_rec;
  l_logmsg_list t_logmsg_list := t_logmsg_list();
  l_logmsg_rec t_logmsg_rec;
  l_max_logmsg_key_id logmsg.KEY_ID%TYPE;
BEGIN
  SELECT NVL(MAX(KEY_ID),1)
    INTO l_max_logmsg_key_id
    FROM logmsg;

  FOR i IN 1..10000 LOOP
    l_max_logmsg_key_id := l_max_logmsg_key_id + 1;
    l_logmsg_rec.key_id        := l_max_logmsg_key_id;
    l_logmsg_rec.msg_id        := 1;
    l_logmsg_rec.session_id    := 666;
    l_logmsg_rec.log_timestamp := current_timestamp;
    l_logmsg_rec.log_pck       := 'perf_test';
    l_logmsg_rec.log_user      := 'fl';
    l_logmsg_rec.log_type      := 1;
    l_logmsg_rec.log_msg       := 'test msg ' ||i;

    l_logmsg_rec.log_apl       := 1;

    l_logmsg_list.EXTEND;
    l_logmsg_list(l_logmsg_list.COUNT) := l_logmsg_rec;
  END LOOP;

  dbms_output.put_line('Start: ' || current_timestamp);

  FORALL l_idx IN 1 .. l_logmsg_list.COUNT
      INSERT INTO logmsg VALUES l_logmsg_list (l_idx);

  dbms_output.put_line('End: ' || current_timestamp);
END;
/

以及表创建脚本：

CREATE TABLE "SCOTT"."LOGMSG" 
(   "KEY_ID" NUMBER(38,0) NOT NULL ENABLE, 
"MSG_ID" NUMBER(38,0) NOT NULL ENABLE, 
"LOG_TYPE" NUMBER(3,0) NOT NULL ENABLE, 
"LOG_TIMESTAMP" TIMESTAMP (6) NOT NULL ENABLE, 
"LOG_USER" VARCHAR2(32 BYTE) NOT NULL ENABLE, 
"LOG_MSG" VARCHAR2(2000 BYTE), 
"LOG_APL" NUMBER(5,0), 
"LOG_ATT" "SYS"."XMLTYPE" , 
"LOG_PCK" VARCHAR2(100 BYTE), 
"SESSION_ID" NUMBER(38,0), 
 CONSTRAINT "PK_LOGMSG" PRIMARY KEY ("KEY_ID")
USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE"  ENABLE
) SEGMENT CREATION IMMEDIATE 
PCTFREE 0 PCTUSED 40 INITRANS 1 MAXTRANS 255 
NOCOMPRESS LOGGING
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_TABLESPACE" 
XMLTYPE COLUMN "LOG_ATT" STORE AS BASICFILE CLOB (
TABLESPACE "SCOTT_TABLESPACE" DISABLE STORAGE IN ROW CHUNK 16384 RETENTION 
NOCACHE LOGGING 
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)) ;

CREATE INDEX "SCOTT"."IX_LOGMSG_1" ON "SCOTT"."LOGMSG" ("MSG_ID") 
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE" ;

CREATE INDEX "SCOTT"."IX_LOGMSG_2" ON "SCOTT"."LOGMSG" ("SESSION_ID") 
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE" ;

CREATE INDEX "SCOTT"."IX_LOGMSG_3" ON "SCOTT"."LOGMSG" ("LOG_TIMESTAMP") 
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 81920 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE" ;

CREATE INDEX "SCOTT"."IX_LOGMSG_C1" ON "SCOTT"."LOGMSG" ("LOG_MSG") 
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE" ;

CREATE INDEX "SCOTT"."IX_LOGMSG_C2" ON "SCOTT"."LOGMSG" ("LOG_PCK") 
PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS 
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "SCOTT_I_TABLESPACE" ;

---

也许您可以尝试另一种方法，避免数组中的逐行填充。我试图用一个大容量收集操作来说明相同的示例。希望能有帮助

set sqlbl on;
DECLARE
  TYPE t_logmsg_tab IS TABLE OF log_msg%ROWTYPE;
  lv_log_msg t_logmsg_tab;
BEGIN


--Since i can see only 10000 values are fetched so here we need not to use LIMIT clause but if
--date volume is more then we need to put LIMIT clause to prevent memory overflow

  SELECT NVL(MAX(KEY_ID) OVER(ORDER BY 1),1)+LEVEL,
         '1'  msg_id,
         '666' session_id,
         current_timestamp,
         'perf_test' log_pck,
         'f1' log_user,
         1 log_type,
         'test msg '||LEVEL,
         '1' log_apl
         BULK COLLECT INTO 
         lv_log_msg
        FROM l_max_logmsg_key_id
        CONNECT BY LEVEL < 10001;

--Not required going for row by row processing will definitely take toll
--So avoiding and performing a bulk Collect Operation


--  SELECT NVL(MAX(KEY_ID),1)
--    INTO l_max_logmsg_key_id
--    FROM logmsg;
--
--  FOR i IN 1..10000 LOOP
--    l_max_logmsg_key_id := l_max_logmsg_key_id + 1;
--    l_logmsg_rec.key_id        := l_max_logmsg_key_id;
--    l_logmsg_rec.msg_id        := 1;
--    l_logmsg_rec.session_id    := 666;
--    l_logmsg_rec.log_timestamp := current_timestamp;
--    l_logmsg_rec.log_pck       := 'perf_test';
--    l_logmsg_rec.log_user      := 'fl';
--    l_logmsg_rec.log_type      := 1;
--    l_logmsg_rec.log_msg       := 'test msg ' ||i;
--
--    l_logmsg_rec.log_apl       := 1;
--
--    l_logmsg_list.EXTEND;
--    l_logmsg_list(l_logmsg_list.COUNT) := l_logmsg_rec;
--  END LOOP;

  IF lv_log_msg.EXISTS(1) THEN

  dbms_output.put_line('Start: ' || current_timestamp);

  FORALL l_idx IN lv_log_msg.FIRST .. lv_log_msg.LAST
      INSERT INTO logmsg VALUES lv_log_msg (l_idx);

  dbms_output.put_line('End: ' || current_timestamp);

  END IF;

END;
/

---

也许您可以尝试另一种方法，避免数组中的逐行填充。我试图用一个大容量收集操作来说明相同的示例。希望能有帮助

set sqlbl on;
DECLARE
  TYPE t_logmsg_tab IS TABLE OF log_msg%ROWTYPE;
  lv_log_msg t_logmsg_tab;
BEGIN


--Since i can see only 10000 values are fetched so here we need not to use LIMIT clause but if
--date volume is more then we need to put LIMIT clause to prevent memory overflow

  SELECT NVL(MAX(KEY_ID) OVER(ORDER BY 1),1)+LEVEL,
         '1'  msg_id,
         '666' session_id,
         current_timestamp,
         'perf_test' log_pck,
         'f1' log_user,
         1 log_type,
         'test msg '||LEVEL,
         '1' log_apl
         BULK COLLECT INTO 
         lv_log_msg
        FROM l_max_logmsg_key_id
        CONNECT BY LEVEL < 10001;

--Not required going for row by row processing will definitely take toll
--So avoiding and performing a bulk Collect Operation


--  SELECT NVL(MAX(KEY_ID),1)
--    INTO l_max_logmsg_key_id
--    FROM logmsg;
--
--  FOR i IN 1..10000 LOOP
--    l_max_logmsg_key_id := l_max_logmsg_key_id + 1;
--    l_logmsg_rec.key_id        := l_max_logmsg_key_id;
--    l_logmsg_rec.msg_id        := 1;
--    l_logmsg_rec.session_id    := 666;
--    l_logmsg_rec.log_timestamp := current_timestamp;
--    l_logmsg_rec.log_pck       := 'perf_test';
--    l_logmsg_rec.log_user      := 'fl';
--    l_logmsg_rec.log_type      := 1;
--    l_logmsg_rec.log_msg       := 'test msg ' ||i;
--
--    l_logmsg_rec.log_apl       := 1;
--
--    l_logmsg_list.EXTEND;
--    l_logmsg_list(l_logmsg_list.COUNT) := l_logmsg_rec;
--  END LOOP;

  IF lv_log_msg.EXISTS(1) THEN

  dbms_output.put_line('Start: ' || current_timestamp);

  FORALL l_idx IN lv_log_msg.FIRST .. lv_log_msg.LAST
      INSERT INTO logmsg VALUES lv_log_msg (l_idx);

  dbms_output.put_line('End: ' || current_timestamp);

  END IF;

END;
/

---

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