Oracle大批量删除数据方法
2024-08-29 13:43:47
供稿：网友
批量删除海量数据通常都是很复杂及缓慢的，方法也很多，但是通常的概念是:分批删除，逐次提交。下面是删除过程，数据表可以通过主键删除，测试过Delete和For all两种方法，for all在这里并没有带来性能提高，所以仍然选择了批量直接删除。 首先创建一下过程，使用自制事务进行处理：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;以下是删除过程及时间:
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)
------------------
11000000Elapsed: 00:00:00.23
SQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 11100000','10000');PL/SQL procedure sUCcessfully completed.Elapsed: 00:00:18.54
SQL> select min(NUMDLFLOGGUID) from HS_DLF_DOWNLOG_HISTORY;MIN(NUMDLFLOGGUID)
------------------
11100000Elapsed: 00:00:00.18
SQL> set serveroutput on
SQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 11200000','10000');
Finished!
Totally 96936 records deleted!PL/SQL procedure successfully completed.Elapsed: 00:00:18.61
10万记录大约19sSQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 11300000','10000');
Finished!
Totally 100000 records deleted!
PL/SQL procedure successfully completed.Elapsed: 00:00:18.62
SQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 11400000','10000');
Finished!
Totally 100000 records deleted!PL/SQL procedure successfully completed.Elapsed: 00:00:18.85
SQL>
SQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 13000000','10000');
Finished!
Totally 1000000 records deleted!PL/SQL procedure successfully completed.Elapsed: 00:03:13.87100万记录大约3分钟
SQL> exec delBigTab('HS_DLF_DOWNLOG_HISTORY','NUMDLFLOGGUID < 20000000','10000');Finished!
Totally 6999977 records deleted!PL/SQL procedure successfully completed.Elapsed: 00:27:24.69
700万大约27分钟以上过程仅供参考.
