Oracle中大批量刪除數據的方法(通過主鍵刪除)

批量刪除海量數據通常都是很複雜及緩慢的，方法也很多，但是通常的概念是:分批刪除，逐次提交。

參見http://blog.csdn.net/robbie1314520/article/details/7816006

下面是另一種刪除過程，我的數據表可以通過主鍵刪除，測試過Delete和For all兩種方法，for all在這裏並沒有帶來性能提高，所以仍然選擇了批量直接刪除。

首先創建一下過程，使用自制事務進行處理：

create or replace procedure delBigTab
(
p_TableName       in    varchar2,
p_Condition       in    varchar2,
p_Count        in    varchar2
)
as
pragma autonomous_transaction;
n_delete number:=0;
begin
while 1=1 loop
EXECUTE IMMEDIATE
'delete from '||p_TableName||' where '||p_Condition||' and rownum <= :rn'
USING p_Count;
if SQL%NOTFOUND then
exit;
else
n_delete:=n_delete + SQL%ROWCOUNT;
end if;
commit;
end loop;
commit;
DBMS_OUTPUT.PUT_LINE('Finished!');
DBMS_OUTPUT.PUT_LINE('Totally '||to_char(n_delete)||' records deleted!');
end;
/

開始：以下是刪除過程及時間:

SQL> create or replace procedure delBigTab
  2  (
  3    p_TableName       in    varchar2,
  4    p_Condition       in    varchar2,
  5    p_Count        in    varchar2
  6  )
  7  as
  8   pragma autonomous_transaction;
  9   n_delete number:=0;
 10  begin
 11   while 1=1 loop
 12     EXECUTE IMMEDIATE
 13       'delete from '||p_TableName||' where '||p_Condition||' and rownum <= :rn'
 14     USING p_Count;
 15     if SQL%NOTFOUND then
 16        exit;
 17     else
 18              n_delete:=n_delete + SQL%ROWCOUNT;
 19     end if;
 20     commit;
 21   end loop;
 22   commit;
 23   DBMS_OUTPUT.PUT_LINE('Finished!');
 24   DBMS_OUTPUT.PUT_LINE('Totally '||to_char(n_delete)||' records deleted!');
 25  end;
 26  /

Procedure created.

SQL> set timing on
SQL> select min(ID) from DEVICE_LOG;

MIN(NUMDLFLOGGUID)
------------------
          11000000

Elapsed: 00:00:00.23
SQL> exec delBigTab('DEVICE_LOG','ID < 11100000','10000');

PL/SQL procedure successfully completed.

Elapsed: 00:00:18.54
SQL> select min(ID) from DEVICE_LOG;

MIN(ID)
------------------
          11100000

Elapsed: 00:00:00.18
SQL> set serveroutput on
SQL> exec delBigTab('DEVICE_LOG','ID < 11200000','10000');
Finished!
Totally 96936 records deleted!

PL/SQL procedure successfully completed.

Elapsed: 00:00:18.61

10萬記錄大約19s

SQL> exec delBigTab('DEVICE_LOG','ID < 11300000','10000');
Finished!
Totally 100000 records deleted!

PL/SQL procedure successfully completed.

Elapsed: 00:00:18.62
SQL> exec delBigTab('DEVICE_LOG','ID < 11400000','10000');
Finished!
Totally 100000 records deleted!

PL/SQL procedure successfully completed.

Elapsed: 00:00:18.85
SQL> 
SQL> exec delBigTab('DEVICE_LOG','ID < 13000000','10000');
Finished!
Totally 1000000 records deleted!

PL/SQL procedure successfully completed.

Elapsed: 00:03:13.87

100萬記錄大約3分鐘

 

SQL> exec delBigTab('DEVICE_LOG','ID < 20000000','10000');
 
Finished!
Totally 6999977 records deleted!

PL/SQL procedure successfully completed.

Elapsed: 00:27:24.69

 

700萬大約27分鐘

轉載eygle