Shrinking a Locally Managed Temporary Tablespace

Question

So, even thoguh the documentation is pretty clear about how to use this feature, I cannot get it to do what I expect it to do for me.
And that would be shrinking the tempfile ;)
Now lets face it, I have a large tempfile and want to resize it without restarting the database:
C:\Users\Administrator>sqlplus / as sysdba
SQL*Plus: Release 11.2.0.2.0 Production on Di Nov 20 05:49:59 2012
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Release 11.2.0.2.0 - 64bit Production
SQL> select file_name
, ceil(bytes / 1024 / 1024) "size MB"
from dba_temp_files
FILE_NAME size MB
R:\MXVC01\TEMP01.DBF 31,231
SQL> select su.username
, ses.sid
, ses.serial#
, su.tablespace
, ceil((su.blocks * dt.block_size) / 1048576) MB
from v$sort_usage su
, dba_tablespaces dt
, v$session ses
where su.tablespace = dt.tablespace_name
and su.session_addr = ses.saddr
USERNAME SID SERIAL# TABLESPACE MB
VPXADMIN 15 15 TEMP 14
VPXADMIN 17 5 TEMP 1,203
VPXADMIN 17 5 TEMP 1
VPXADMIN 18 3 TEMP 7
VPXADMIN 19 3 TEMP 1
VPXADMIN 144 3 TEMP 1
VUMADMIN 156 2597 TEMP 1
7 rows selected.
Or this one:
SQL> select tablespace_size/1024/1024 "tablespace_size mb"
, allocated_space/1024/1024 "allocated_space mb"
, free_space/1024/1024 "free_space mb"
from dba_temp_free_space
tablespace_size mb allocated_space mb free_space mb
31230,9922 1228,99219 30002
Documetation from here: http://docs.oracle.com/cd/E11882_01/server.112/e25494/tspaces007.htm#ADMIN12353
+"Shrinking a Locally Managed Temporary Tablespace+
+Large sort operations performed by the database may result in a temporary tablespace growing and occupying a considerable amount of disk space. After the sort operation completes, the extra space is not released; it is just marked as free and available for reuse. Therefore, a single large sort operation might result in a large amount of allocated temporary space that remains unused after the sort operation is complete. For this reason, the database enables you to shrink locally managed temporary tablespaces and release unused space.+
+You use the SHRINK SPACE clause of the ALTER TABLESPACE statement to shrink a temporary tablespace, or the SHRINK TEMPFILE clause of the ALTER TABLESPACE statement to shrink a specific tempfile of a temporary tablespace. Shrinking frees as much space as possible while maintaining the other attributes of the tablespace or tempfile. The optional KEEP clause defines a minimum size for the tablespace or tempfile.+
+Shrinking is an online operation, which means that user sessions can continue to allocate sort extents if needed, and already-running queries are not affected.+
+The following example shrinks the locally managed temporary tablespace lmtmp1 to a size of 20M.+
+ALTER TABLESPACE lmtemp1 SHRINK SPACE KEEP 20M;+
+The following example shrinks the tempfile lmtemp02.dbf of the locally managed temporary tablespace lmtmp2. Because the KEEP clause is omitted, the database attempts to shrink the tempfile to the minimum possible size.+
+ALTER TABLESPACE lmtemp2 SHRINK TEMPFILE '/u02/oracle/data/lmtemp02.dbf';"+
OK, lets do it:
SQL> alter tablespace temp shrink tempfile 'R:\MXVC01\TEMP01.DBF';
alter tablespace temp shrink tempfile 'R:\MXVC01\TEMP01.DBF'
ERROR at line 1:
ORA-03214: File Size specified is smaller than minimum required
It seems there is a bug? Should I report it, or is it the expected behaviour?
Now lets try this one:
SQL> alter tablespace temp shrink tempfile 'R:\MXVC01\TEMP01.DBF' keep 2048M;
Tablespace altered.
SQL> select file_name
, ceil(bytes / 1024 / 1024) "size MB"
from dba_temp_files
FILE_NAME size MB
R:\MXVC01\TEMP01.DBF 31,231
So .... this lasts about *10 minutes*, and nothing changes?
It seems there is a bug? Should I report it, or is it the expected behaviour?
Could someone enlighten me, what this SHRINK is actually doing?
Is it worth to report this as bug, if not a software bug it is at least a documentation bug because it doesn't mention under which conditions it is working?
P.S.: OMG the posting looks terrible, who's the one to blame for this forum software where it is not possible to use fixed size fonts, or format paragraphs as code, or what about the fact that the forum software is using default SQLPlus output as META for some graphical lines?
Isn't this the forum for Oracle Database users?
Edited by: Gerrit Haase on 20.11.2012 13:44

Answer 1

So, you are kidding with me? No? Who are you?
How can I block users here? Is there a moderator present at this forum?
Maybe you read my initial post again?
I didn't look at the wrong place.
I reported you for general abuse.
SQL> define
DEFINE _DATE           = "20.11.12" (CHAR)
DEFINE CONNECTIDENTIFIER = "MXVC01" (CHAR)
DEFINE _USER           = "SYS" (CHAR)
DEFINE _PRIVILEGE      = "AS SYSDBA" (CHAR)
DEFINE SQLPLUSRELEASE = "1102000200" (CHAR)
DEFINE _EDITOR         = "Notepad" (CHAR)
DEFINE OVERSION = "Oracle Database 11g Release 11.2.0.2.0 - 64bit Production" (CHAR)
DEFINE ORELEASE = "1102000200" (CHAR)
SQL> SELECT * FROM dba_temp_free_space;
TABLESPACE_NAME TABLESPACE_SIZE ALLOCATED_SPACE FREE_SPACE
TEMP 3,2748E+10 1306517504 3,1443E+10
SQL> select TABLESPACE_SIZE/power(2,20), ALLOCATED_SPACE/power(2,20), FREE_SPACE/power(2,20) from dba_temp_free_space ;
TABLESPACE_SIZE/POWER(2,20) ALLOCATED_SPACE/POWER(2,20) FREE_SPACE/POWER(2,20)
31230,9922 1245,99219 29986
SQL> ALTER TABLESPACE temp SHRINK SPACE;
Tablespace altered.
SQL> select TABLESPACE_SIZE/power(2,20), ALLOCATED_SPACE/power(2,20), FREE_SPACE/power(2,20) from dba_temp_free_space ;
TABLESPACE_SIZE/POWER(2,20) ALLOCATED_SPACE/POWER(2,20) FREE_SPACE/POWER(2,20)
31230,9922 1244,99219 *29986*
R:\mxvc01>dir temp
Volume in drive R is Disk_R
Volume Serial Number is 248B-61D4
Directory of R:\mxvc01
20.11.2012 08:09 32.748.077.056 TEMP01.DBF
1 File(s) 32.748.077.056 bytes
0 Dir(s) 8.259.297.280 bytes free
SQL> alter tablespace temp shrink tempfile 'R:\mxvc01\TEMP01.DBF';
alter tablespace temp shrink tempfile 'R:\mxvc01\TEMP01.DBF'
ERROR at line 1:
ORA-03214: File Size specified is smaller than minimum required
*It clearly says that there is 29986 MB Space FREE and the above shrink space changes nothing and so does shrink tempfile:*
SQL> alter tablespace temp shrink tempfile 'R:\mxvc01\TEMP01.DBF';
alter tablespace temp shrink tempfile 'R:\mxvc01\TEMP01.DBF'
ERROR at line 1:
ORA-03214: File Size specified is smaller than minimum required
SQL> alter tablespace temp shrink tempfile 'R:\mxvc01\TEMP01.DBF' KEEP 20M;
Tablespace altered.
R:\mxvc01>dir temp
Volume in drive R is Disk_R
Volume Serial Number is 248B-61D4
Directory of R:\mxvc01
20.11.2012 08:24 32.748.077.056 TEMP01.DBF
1 File(s) 32.748.077.056 bytes
0 Dir(s) 8.259.280.896 bytes free
*... nothing changes, the tempfile isn't smaller now ...*