首先on commit preserve rows 和 on commit delete rows 都是在oracle 创建临时表时用到的, delete rows用于事务相关,也就在事务结束后truncate data in the temporary table. preserve rows表示在会话结束后清除临时表的数据 前者在事务提交后数据就已经清除了. 后者在会话中止时或者导常退出时数据都会被清除掉....
恢复delete 的rows Whenrows are deletedinOracle the dataisnotactually removed. The rowissimplymarkedasdeletedandthe freespacecountersandpointers adjustedaccordingly. The statusofa rowisstoredinthe Row Header which occupies thefirst few bytesofeach row. 当row 被delete 的时候,实际上data 并没有被remove,...
Class_Memo varchar2(200)) on Commit delete Rows ; 3) 两中类型临时表的区别 会话级临时表采用 on commit preserve rows ;而事务级则采用 on commit delete rows ;用法上,会话级别只有当会话结束临时表中的数据才会被截断,而且事务级临时表则不管是 commit 、 rollback 或者是会话结束,临时表中的数据都将被...
obclient> DELETE FROM (SELECT * FROM tbl1); Query OK, 4 rows affected obclient> SELECT * FROM tbl1; Empty set 单表删除:包含 RETURNING 子句。 obclient> DELETE FROM tbl1 RETURNING col1; +---+ | COL1 | +---+ | 1 | | 2 | | 3 | | 4 | +---+ 4 rows in set obclient...
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 ...
obclient> DELETE FROM (SELECT * FROM tbl1); Query OK, 4 rows affected obclient> SELECT * FROM tbl1; Empty set 单表删除:包含 RETURNING 子句。 obclient> DELETE FROM tbl1 RETURNING col1; +---+ | COL1 | +---+ | 1 | | 2 | | 3 | | 4 | +---+ 4 rows in set obclient...
4 rows selected. 删除指定的内容 SQL> CREATE TABLE project ( 2 pro_id NUMBER(4), 3 pro_name VARCHAR2(40), 4 budget NUMBER(9,2), 5 CONSTRAINT project_pk PRIMARY KEY (pro_id) 6 ); Table created. SQL> SQL> SQL> INSERT INTO project(pro_id, pro_name, budget)VALUES (1001, 'A',...
int delete_rows=10000; ... 1. CHAR类型数组变量 EXEC SQL for :delete_rows delete FROM table_name WHERE a= :a; 由于char对应于Oracle的char类型,因此若有空格,则此时char即使用memset初始化,但也会带有后面的空格,有可能造成delete时where a=:a由于空格不匹配无法删除,例如:a赋值为'a’,但数组长度是...
499995 rows deleted. commit; 5、再查看空间使用情况75% – % freespace blocks从DELETE前237 增长到 71665。 set serverout on exec show_space('TAB','TEST'); SQL> SQL> Total Blocks...589824 Total Bytes...4831838208 Unused Blocks...0 Unused Bytes...0 Last Used Ext FileId...23 Last...
SQLgt; SQLgt; SQLgt; SQLgt; SQLgt; SQLgt; SQLgt; -- delete command with conditions SQLgt; SQLgt; delete from Employee where Salary gt; 3000; 4 rows deleted. SQLgt; SQLgt; select * from Employee; ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION 01 Jason Martin ...