purge recyclebin之后dba_segments仍然有BIN$段。
如下，执行了purge recyclebin之后：
SQL> select segment_name,SEGMENT_TYPE from dba_segments where tablespace_name like 'USERS' and owner='ZHOU186'
2 ;
SEGMENT_NAME SEGMENT_TYPE
--------------------------------------------------------------------------------- ------------------
BIN$xd87Y+adofPgQAB/AQB9yA==$0 TABLE
BIN$xd87Y+acofPgQAB/AQB9yA==$0 TABLE
ZHOU_WORK_UNITE_ TABLE
ZHOU_WORK_UNITE_ TABLE
ZHOU_WORK_UNITE_ TABLE
BIN$0QhC65ubuMzgQAB/AQBaBg==$0 TABLE
ZHOU_WORK_UNITE_ TABLE
ZHOU_WORK_UNITE_ TABLE
BIN$wJ9k2G65qpDgQAB/AQAj+g==$0 TABLE
ZHOU_WORK_UNITE_ TABLE
BIN$0QhC65uauMzgQAB/AQBaBg==$0 TABLE
ZHOU_WORK_UNITE_ TABLE
BIN$0QhC65uduMzgQAB/AQBaBg==$0 TABLE
BIN$0QhC65ucuMzgQAB/AQBaBg==$0 TABLE
SQL> desc ZHOU186."BIN$xd87Y+adofPgQAB/AQB9yA==$0";
Name Null Type
----------------------------------------------------------------------------------------------------------------- -------- ----------------------------------------------------------------------------
BEGIN_DATE VARCHAR2(10)
BEGIN_TIME VARCHAR2(10)
END_DATE VARCHAR2(10)
END_TIME VARCHAR2(10)
POSITION1 VARCHAR2(30)
PRG_NUM VARCHAR2(30)
WORK_TIME FLOAT(126)
FIRST_CHECK NUMBER(38)
PERSON_NUMBER VARCHAR2(20)
JOB_BIN VARCHAR2(20)
JOB_BINNUMBER NUMBER(38)
分析：
客户的操作步骤大致是：
[oracle@MESZHOUDB ~]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.4.0 - Production on Thu May 16 09:55:40 2013
Copyright (c) 1982, 2007, Oracle. All Rights Reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL>
SQL> alter session set current_schema=ZHOU186; <====注意到是set current_schema，并不是直接登录进来
Session altered.
SQL> purge recyclebin;
Recyclebin purged.
SQL>
SQL>
SQL> select segment_name from dba_segments where tablespace_name like 'USERS' and owner='ZHOU186'
2 ;
SEGMENT_NAME
--------------------------------------------------------------------------------
BIN$xd87Y+adofPgQAB/AQB9yA==$0
BIN$xd87Y+acofPgQAB/AQB9yA==$0
ZHOU_WORK_UNITE_
ZHOU_WORK_UNITE_
ZHOU_WORK_UNITE_
BIN$0QhC65ubuMzgQAB/AQBaBg==$0
ZHOU_WORK_UNITE_
ZHOU_WORK_UNITE_
BIN$wJ9k2G65qpDgQAB/AQAj+g==$0
ZHOU_WORK_UNITE_
BIN$0QhC65uauMzgQAB/AQBaBg==$0
SEGMENT_NAME
--------------------------------------------------------------------------------
ZHOU_WORK_UNITE_
BIN$0QhC65uduMzgQAB/AQBaBg==$0
BIN$0QhC65ucuMzgQAB/AQBaBg==$0
BIN$0QhC65ueuMzgQAB/AQBaBg==$0
ZHOU_WORK_UNITE_
BIN$w2uuBw1tJa/gQAB/AQB7Eg==$0
BIN$w2uuBw1sJa/gQAB/AQB7Eg==$0
BIN$w2uuBw1uJa/gQAB/AQB7Eg==$0
BIN$w2uuBw1vJa/gQAB/AQB7Eg==$0
Oracle文档的说明：
The CURRENT_SCHEMA parameter changes the current schema of the session to the specified schema. Subsequent unqualified references to schema objects during the session will resolve to objects in the specified schema.
This setting offers a convenient way to perform operations on objects in a schema other than that of the current user without having to qualify the objects with the schema name. This setting changes the current schema, but it does not change the session user or the current user, nor does it give the session user any additional system or object privileges for the session.
For example:
T