这段时间系统由于大量历史数据造成应用响应缓慢，需要对大量历史数据做数据迁移，原本计划将原表备份后Create table as 一个新表，量表换名重建索引等解决，但由于服务层的特殊结构，这些表无法做分区，而且这种方式直接会将服务整挂，所以想采用delete掉数据重新压缩表空间和索引方式解决。
预计删除数据量为12个大表，每个表总量为3000W-3亿数据，需要清除2/3的数据，采取步骤如下，以供日后整理
- 备份数据
备份数据量需要表空间空余500G，现workflow空余表空间只有90G,需要扩展至少500G
Step.1备份故障和投诉主工单
表名 备注
T367 故障主工单T表(WF:BMCC_EOMS_ITDealFault)
H367 故障主工单H表(WF:BMCC_EOMS_ITDealFault)
T633 投诉主工单T表(WF:BJ_EOMS_Complaint)
H633 投诉主工单H表(WF:BJ_EOMS_Complaint)
远程dblink备份语句示例
Create table T367 as select * from [email protected]_product;
Step.2备份工单辅助表
表名 备注
T117 工单状态表（WF:App_Base_Infor）
T118 工单通知表（WF:App_Base_Notice）
T136 工单环节表（WF:App_DealProcess）
T135 工单流程线表（WF:App_DealLink）
T134 工单开始结束状态表（WF:App_DealAssistantProcess）
T141 工单流程判断表（WF:App_DealVerdict）
T363 工单流转线表（WF:App_DealGoLine）
T114 工单字段修改记录表（WF:App_Base_FieldModifyLog）
- 查询数据量
1.故障T表
select count(1) from t367 WHERE 1=1 AND c3<1380513600
2.投诉T表
select count(1) from t633 WHERE 1=1 AND c3<1380513600
2.其它辅助表
select count(1) from t136 WHERE 1=1 AND (C700020002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 select count(1) from T135 WHERE 1=1 AND (C700020502 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020502=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; select count(1) from T134 WHERE 1=1 AND (C700020802 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020802=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; select count(1) from T141 WHERE 1=1 AND (C700020602 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020602=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; select count(1) from T114 WHERE 1=1 AND (C700021002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700021002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; select count(1) from T118 WHERE 1=1 AND (C700050002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700050002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3>1380513600;
- 新建临时表
新建临时表（存要删数据的rowid）
语句：
CREATE TABLE ROWID_T633 AS SELECT ROWID ID,C1 FROM T633 WHERE C3 < 1380513600 CREATE TABLE ROWID_T367 AS SELECT ROWID ID,C1 FROM T633 WHERE C3 < 1380513600 CREATE TABLE ROWID_T117 AS SELECT ROWID AS ID FROM T117 WHERE 1=1 AND (C700020002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 CREATE TABLE ROWID_T135 AS SELECT ROWID AS ID FROM T135 WHERE 1=1 AND (C700020502 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020502=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; CREATE TABLE ROWID_T134 AS SELECT ROWID AS ID FROM T134 WHERE 1=1 AND (C700020802 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020802=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; CREATE TABLE ROWID_T141 AS SELECT ROWID AS ID FROM T141 WHERE 1=1 AND (C700020602 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020602=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; CREATE TABLE ROWID_T114 AS SELECT ROWID AS ID FROM T114 WHERE 1=1 AND (C700021002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700021002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ; CREATE TABLE ROWID_T136 AS SELECT ROWID AS ID FROM T136 WHERE 1=1 AND (C700020002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600; CREATE TABLE ROWID_H633 AS SELECT ROWID ID,Entryid FROM H633 WHERE T0 < 1380513600 CREATE TABLE ROWID_H367 AS SELECT ROWID ID,Entryid FROM H367 WHERE T0 < 1380513600 CREATE TABLE ROWID_T118 AS SELECT ROWID AS ID FROM T118 WHERE 1=1 AND (C700050002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700050002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3>1380513600;
- 写脚本删除
T117
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T117) LOOP
DELETE FROM T117 WHERE ROWID=tr.id;
n:=n+1;
IF MOD(n,5000)=0 THEN
COMMIT;
END IF;
END LOOP;
COMMIT;
END;
T367
DECLARE n NUMBER :=0; BEGIN FOR tr IN (SELECT ID FROM ROWID_T367) LOOP DELETE FROM T367 WHERE ROWID=tr.id; n:=n+1; IF MOD(n,5000)=0 THEN COMMIT; END IF; END LOOP; COMMIT; END;
T633
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T633) LOOP
DELETE FROM T633 WHERE ROWID=tr.id;
n:=n+1; IF MOD(n,5000)=0 THEN COMMIT; END IF;
END LOOP;
COMMIT;
END;
T134
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T134) LOOP
DELETE FROM T134 WHERE ROWID=tr.id;
n:=n+1; IF MOD(n,5000)=0 THEN COMMIT; END IF;
END LOOP;
COMMIT;
END;
…
- 剩余表迁移数据工作步骤
重建T表（T135、T136、T114、T141）的临时表CREATE TABLE ROWID_T135 AS SELECT ROWID AS ID FROM T135 WHERE 1=1 AND (C700020502 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020502=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ;
CREATE TABLE ROWID_T141 AS SELECT ROWID AS ID FROM T141 WHERE 1=1 AND (C700020602 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020602=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ;
CREATE TABLE ROWID_T114 AS SELECT ROWID AS ID FROM T114 WHERE 1=1 AND (C700021002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700021002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ;
CREATE TABLE ROWID_T136 AS SELECT ROWID AS ID FROM T136 WHERE 1=1 AND (C700020002 = ‘WF:BMCC_EOMS_ITDealFault‘ OR C700020002=‘WF:BJ_EOMS_COMPLAINT‘) AND c3<1380513600 ;执行脚本删除数据
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T135) LOOP
DELETE FROM T135 WHERE ROWID=tr.id;
n:=n+1;
IF MOD(n,5000)=0 THEN
COMMIT;
END IF;
END LOOP;
COMMIT;
END;
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T136) LOOP
DELETE FROM T136 WHERE ROWID=tr.id;
n:=n+1;
IF MOD(n,5000)=0 THEN
COMMIT;
END IF;
END LOOP;
COMMIT;
END;
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T114) LOOP
DELETE FROM T114 WHERE ROWID=tr.id;
n:=n+1; IF MOD(n,5000)=0 THEN COMMIT; END IF;
END LOOP;
COMMIT;
END;
DECLARE n NUMBER :=0;
BEGIN
FOR tr IN (SELECT ID FROM ROWID_T141) LOOP
DELETE FROM T141 WHERE ROWID=tr.id;
n:=n+1; IF MOD(n,5000)=0 THEN COMMIT; END IF;
END LOOP;
COMMIT;
END;
- 释放表空间
–打开行锁
alter table T118 enable row MOVEMENT
–整理数据和索引
alter TABLE T118 shrink space COMPACT CASCADE
–释放表空间
alter TABLE T118 shrink SPACE CASCADE