Oracle 临时表空间 temp表空间切换

一.TEMP表空间

临时表空间主要用途是在数据库进行排序运算、管理索引、访问视图等操作时提供临时的运算空间，当运算完成之后系统会自动清理。当oracle里需要用到sort的时候，PGA中sort_area_size大小不够时，将会把数据放入临时表空间里进行排序，同时如果有异常情况的话，也会被放入临时表空间,正常来说，在完成Select语句、create index等一些使用TEMP表空间的排序操作后，Oracle是会自动释放掉临时段的。注意这里的释放，仅仅是将这些空间标记为空闲，并可重用，真正占用的磁盘空间并没有释放。所以Temp表空间可能会越来越大。

排序是很耗资源的，Temp表空间满了,关键是优化你的语句，尽量使排序减少才是上策.

二、oracle temp表空间切换

查询temp表空间、创建temp2表空间5000m、切换临时表空间为 temp2、 删除临时表空间temp

oracle@xyy:/home/oracle> sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Fri Oct 11 14:18:44 2013

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> SELECT temp_used.tablespace_name, total - used as "Free", total as "Total", round(nvl(total - used, 0) * 100 / total, 3) "Free percent"
  2  FROM (SELECT tablespace_name, SUM(bytes_used)/1024/1024 used FROM GV$TEMP_SPACE_HEADER GROUP BY tablespace_name) temp_used,
  3  (SELECT tablespace_name, SUM(bytes)/1024/1024 total FROM dba_temp_files GROUP BY tablespace_name) temp_total
  4  WHERE temp_used.tablespace_name = temp_total.tablespace_name;

TABLESPACE_NAME                        Free      Total Free    percent
------------------------------ ---------- ---------- ------------
TEMP                                                           0         29            0

SQL> create temporary tablespace temp2 tempfile '/home/oracle/ora11g/oradata/xyy/temp02.dbf' size 5000M autoextend off;

Tablespace created.

SQL> alter database default temporary tablespace temp2;

Database altered.

SQL> drop tablespace temp;

Tablespace dropped.

SQL> SELECT temp_used.tablespace_name, total - used as "Free", total as "Total", round(nvl(total - used, 0) * 100 / total, 3) "Free percent"
  2  FROM (SELECT tablespace_name, SUM(bytes_used)/1024/1024 used FROM GV$TEMP_SPACE_HEADER GROUP BY tablespace_name) temp_used,
  3  (SELECT tablespace_name, SUM(bytes)/1024/1024 total FROM dba_temp_files GROUP BY tablespace_name) temp_total
  4  WHERE temp_used.tablespace_name = temp_total.tablespace_name;

TABLESPACE_NAME                      Free      Total           Free  percent
------------------------------ ---------- ---------- ------------
TEMP2                                              4998            5000                99.96

temp表空间的 tempfile 为 temp01.dbf, 删除 temp01.dbf
oracle@xyy:/home/oracle/ora11g/oradata/xyy> ll
total 3297068
-rw-r----- 1 oracle oinstall    9748480 Oct 11 14:31 control01.ctl
-rw-r----- 1 oracle oinstall    9748480 Oct 11 14:31 control02.ctl
-rw-r----- 1 oracle oinstall  328343552 Oct 11 14:31 example01.dbf
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo01.log
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo02.log
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo03.log
-rw-r----- 1 oracle oinstall  566239232 Oct 11 14:31 sysaux01.dbf
-rw-r----- 1 oracle oinstall  744497152 Oct 11 14:31 system01.dbf
-rw-r----- 1 oracle oinstall 5242888192 Oct 11 14:29 temp01.dbf
-rw-r----- 1 oracle oinstall 5242888192 Oct 11 14:21 temp02.dbf
-rw-r----- 1 oracle oinstall   99622912 Oct 11 14:31 undotbs01.dbf
-rw-r----- 1 oracle oinstall    5251072 Oct 11 14:31 users01.dbf

oracle@xyy:/home/oracle/ora11g/oradata/xyy>rm temp01.dbf

查询当前临时表空间

SQL> select username,temporary_tablespace from dba_users;

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
SYS                                      TEMP2
SYSTEM                              TEMP2
OUTLN                                TEMP2
MGMT_VIEW                      TEMP2
FLOWS_FILES                  TEMP2
MDSYS                                TEMP2
ORDSYS                             TEMP2
EXFSYS                               TEMP2
DBSNMP                             TEMP2
WMSYS                                TEMP2
APPQOSSYS                      TEMP2

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
APEX_030200                     TEMP2
OWBSYS_AUDIT                 TEMP2
ORDDATA                             TEMP2
CTXSYS                                TEMP2
ANONYMOUS                      TEMP2
SYSMAN                                TEMP2
XDB                                        TEMP2
ORDPLUGINS                     TEMP2
OWBSYS                               TEMP2
SI_INFORMTN_SCHEMA   TEMP2
OLAPSYS                              TEMP2

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
SCOTT                                    TEMP2
ORACLE_OCM                     TEMP2
XS$NULL                               TEMP2
BI                                             TEMP2
PM                                           TEMP2
MDDATA                                 TEMP2
IX                                             TEMP2
SH                                           TEMP2
DIP                                          TEMP2
OE                                           TEMP2
APEX_PUBLIC_USER        TEMP2

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
HR                                                         TEMP2
SPATIAL_CSW_ADMIN_USR          TEMP2
SPATIAL_WFS_ADMIN_USR           TEMP2

36 rows selected.

创建临时表空间temp为5000m、切换临时表空间为temp表空间、查询数据库临时表空间使用、删除临时表空间temp2

SQL> create temporary tablespace temp tempfile '/home/oracle/ora11g/oradata/xyy/temp01.dbf' size 5000M autoextend off;

Tablespace created.

SQL> alter database default temporary tablespace temp;

Database altered.

SQL> select username,temporary_tablespace from dba_users;

USERNAME                       TEMPORARY_TABLESPACE
------------------------------    ------------------------------
SYS                                        TEMP
SYSTEM                                TEMP
FLOWS_FILES                     TEMP
MDSYS                                  TEMP
ORDSYS                              TEMP
EXFSYS                               TEMP
DBSNMP                             TEMP
SCOTT                                 TEMP
WMSYS                               TEMP
ORACLE_OCM                   TEMP
APPQOSSYS                      TEMP

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
XS$NULL                            TEMP
APEX_030200                    TEMP
OWBSYS_AUDIT              TEMP
BI                                         TEMP
PM                                       TEMP
MDDATA                             TEMP
IX                                          TEMP
ORDDATA                          TEMP
CTXSYS                             TEMP
ANONYMOUS                   TEMP
SH                                       TEMP

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
OUTLN                                TEMP
DIP                                       TEMP
OE                                       TEMP
APEX_PUBLIC_USER               TEMP
HR                                       TEMP
SYSMAN                            TEMP
XDB                                    TEMP
SPATIAL_CSW_ADMIN_USR          TEMP
SPATIAL_WFS_ADMIN_USR          TEMP
ORDPLUGINS                                    TEMP
OWBSYS                                             TEMP

USERNAME                       TEMPORARY_TABLESPACE
------------------------------ ------------------------------
MGMT_VIEW                                   TEMP
SI_INFORMTN_SCHEMA             TEMP
OLAPSYS                                        TEMP

SQL> drop tablespace temp2;

Tablespace dropped.

oracle@xyy:/home/oracle/ora11g/oradata/xyy>ll
total 3297068
-rw-r----- 1 oracle oinstall    9748480 Oct 11 14:31 control01.ctl
-rw-r----- 1 oracle oinstall    9748480 Oct 11 14:31 control02.ctl
-rw-r----- 1 oracle oinstall  328343552 Oct 11 14:31 example01.dbf
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo01.log
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo02.log
-rw-r----- 1 oracle oinstall  536871424 Oct 11 14:31 redo03.log
-rw-r----- 1 oracle oinstall  566239232 Oct 11 14:31 sysaux01.dbf
-rw-r----- 1 oracle oinstall  744497152 Oct 11 14:31 system01.dbf
-rw-r----- 1 oracle oinstall 5242888192 Oct 11 14:29 temp01.dbf
-rw-r----- 1 oracle oinstall 5242888192 Oct 11 14:21 temp02.dbf
-rw-r----- 1 oracle oinstall   99622912 Oct 11 14:31 undotbs01.dbf
-rw-r----- 1 oracle oinstall    5251072 Oct 11 14:31 users01.dbf

oracle@xyy:/home/oracle/ora11g/oradata/xyy>rm temp02.dbf