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
