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Oracle中大批量删除数据的方法

發布時間：2023/12/18 编程问答 37 豆豆

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批量刪除海量數據通常都是很復雜及緩慢的，方法也很多，但是通常的概念是:分批刪除，逐次提交。
下面是我的刪除過程，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在這里并沒有帶來性能提高，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;

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(NUMDLFLOGGUID) from HS_DLF_DOWNLOG_HISTORY;

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

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