--11g 以后关闭回收站 system 级别需要加 DEFERRED 参数；---session 级别不需要
select name,isses_modifiable,issys_modifiable from v$parameter where name='recyclebin'
SQL> show parameter recyclebin
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
recyclebin string on
SQL> alter system set recyclebin=off; alter system set recyclebin=off
* ERROR at line 1: ORA-02096: specified initialization parameter is not modifiable with this option
SQL> alter system set recyclebin=off DEFERRED;
System altered.
SQL> show parameter recyclebin
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
recyclebin string on
SQL> exit
Disconnected from Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
[oracle@dwdb1 ~]$ sqlplus / as sysdba
SQL*Plus: Release 12.2.0.1.0 Production on Tue Dec 19 14:11:18 2017
Copyright (c) 1982, 2016, Oracle. All rights reserved.
Connected to: Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
SQL> show parameter recyclebin
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
recyclebin string OFF
删除回收站所有垃圾信息： PURGE recyclebin; purge dba_RECYCLEBIN;
SQL> show pdbs;
CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 DSDB READ WRITE NO
4 DWDB READ WRITE NO
SQL> alter session set container=DSDB;
Session altered.
SQL> purge dba_RECYCLEBIN;
DBA Recyclebin purged.
SQL> show parameter recyclebin
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
recyclebin string OFF
SQL> alter session set container=DWDB;
Session altered.
SQL> SELECT count(1) FROM dba_RECYCLEBIN;
COUNT(1) ---------- 0
SQL> show parameter recyclebin
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
recyclebin string OFF
日积月累
