Introduction to the Oracle DELETE statement To delete one or more rows from a table, you use the OracleDELETEstatement as follows: DELETEFROMtable_nameWHEREcondition;Code language:SQL (Structured Query Language)(sql) In this statement, First, you specify the name of the table from which you wa...
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...
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 2. 可以truncate...
When you delete rows from an updatable view, Oracle Database deletes rows from the base table. You cannot delete rows from a read-only materialized view. If you delete rows from a writable materialized view, then the database removes the rows from the underlying container table. However, the...
ename | deptno ---+--- ALLEN | 30 WARD | 30 MARTIN | 30 BLAKE | 30 CLARK | 10 KING | 10 TURNER | 30 JAMES | 30 MILLER | 10 (9 rows) 在执行不带WHERE子句的DELETE命令(如下所示)时,要非常小心: DELETE FROM tablename; 此语句会删除给定表中的所有行,使该表完全为空。且在执行此操作...
obclient> CREATE TABLE tbl1(col1 INT PRIMARY KEY, col2 INT); Query OK, 0 rows affected obclient> INSERT INTO tbl1 VALUES(1,1),(2,2),(3,3),(4,4); Query OK, 4 rows affected Records: 4 Duplicates: 0 Warnings: 0 obclient> SELECT * FROM tbl1; +---+---+ | COL1 | COL...
create global temporary table Classes ( Class_id Number(5), Class_Name Varchar2(8), 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...
obclient> CREATE TABLE tbl1(col1 INT PRIMARY KEY, col2 INT); Query OK, 0 rows affected obclient> INSERT INTO tbl1 VALUES(1,1),(2,2),(3,3),(4,4); Query OK, 4 rows affected Records: 4 Duplicates: 0 Warnings: 0 obclient> SELECT * FROM tbl1; +---+---+ | COL1 | COL...
Oracle Delete Statements Version 10.2 Basic Delete Statements 1.Delete All Rows: DELETE <table_name> or DELETE FROM <table_name>; CREATE TABLE t AS SELECT * FROM all_tables; SELECT COUNT(*) FROM t; DELETE FROM t; COMMIT; SELECT COUNT(*) ...
现象：After database upgrade to 11.2.0.4 cannot delete any rows from a table with context ...