1 row deleted.Code language:SQL (Structured Query Language)(sql) B) Oracle DELETE – delete multiple rows from a table The following statement deletes all rows whose order id is 1: DELETEFROMsalesWHEREorder_id =1;Code language:SQL (Structured Query Language)(sql) ...
1 row created. SQL> insert into t2 values (2,'digoal'); 1 row created. SQL> commit; Commit complete. 下面来写个类似的delete语句 : SQL> delete from (select * from t1,t2 where t1.id=1 and t2.id=t1.id and t2.info='digoal'); 1 row deleted. SQL> select * from t2; ID INFO ...
方法1 declarecursor[del_cursor]isselecta.*, a.rowid row_idfrom[table_name]aorderbya.rowid;beginforv_cusorin[del_cursor]loopifv_cusor.[time_stamp]<to_date('2014-01-01','yyyy-mm-dd')thendeletefrom[table_name]whererowid=v_cusor.row_id;endif;ifmod([del_cursor]%rowcount,1000)=0thenc...
针对delete操作引起的空间不释放现象,或者,更正式一点的说法,如何降低高水位线,方法有很多种,如,shrink space;move tablespace;create table xxx as select * from xxx 重建表等。使用这些方法前,我们的原则是: 如果可以truncate,直接truncate,该操作会重置高水位线,BLOCKS会被置为0,NUM_ROWS置为0;否则,优先使用sh...
1、使用ROW_NUMBER()为每个重复组分配一个唯一的序号。 2、删除序号大于1的所有记录。 代码示例: DELETE FROM ( SELECT row_number() OVER (PARTITION BY duplicated_columns ORDER BY some_column) AS rn FROM your_table ) WHERE rn > 1; 方法三:使用临时表 ...
大表中海量历史数据的更新与删除一直是一件非常头痛的事情,在表已经分区的前提下我们还可以利用并行或者truncate parition等手段来为UPDATE或者DELETE提速, 但是如果对象是普通的非分区对表(non-partitioned heap table)的话,似乎就没有太好的加速方法了, nologging或parallel 对非分区表都没有效果。
DELETE FROM emp_copy WHERE department_id = (SELECT department_id FROM departments WHERE department_name LIKE '%Public%'); TRUNCATE TABLE table_name; TRUNCATE TABLE copy_emp; 自动提交,不能回滚。不能加where子句。产生日志少,几乎不产生undo数据,速度快。会释放空间,delete后不会释放空间。
alter table 表名 enable row movement flashback table 表名 to timestamp to_timestamp(删除时间点',' frombyte yyyy-mm-dd hh24:mi:ss') 北亚企安数据恢复—oracle数据恢复 2、drop误删除的数据恢复方法。 oracle在删除表时没有直接将表所占的块清空,只是对该表的数据块做了可以被覆写的标志。oracle将已...
select TABLE_NAME,NUM_ROWS from dba_tables where OWNER='xxx' order by NUM_ROWS desc; 1. 整理好后交给开发,确认各大表是否可清理,需保存多久数据。 二、 清理分类 目前大致遇到以下几种场景: 1. 可以drop 备份表、临时表、已无用的表 时间范围分区表:索引改为local索引后,按分区drop ...
delete from "BISAL"."T_FLASH_01" where "COL 1" = HEXTORAW('c INSERTlues (HEXTORAW('c104'),HEXTORAW('63'),HEXTORAW('63')); 104') and "COL 2" = HEXTORAW('63') and "COL 3" = HEXTORAW('6 3') and ROWID = 'AAAR7ZAAMAAACqNAAC';ALTER TABLE t_flash_01 enable ROW movement; ...