What is tablespace fragmentation?

hello all,
please,give me more detail about tablespace fragmentation .i want to know when tablespace fragmentation occur? thanks all in advance for response.

first thanks u and all for give me response and this wonderful link but i have a doubt which i want to ask ,when table is dropped,or truncated or raw of table is deleted then free extents is available for another request, if a request is made for an extent allocation that cannot be found in one free contiguous extent even though the total free space in the tablespace may be significantly larger than the requested size. is this a fragmentation problem?

Similar Messages

What is the difference between Table & Tablespace Fragmentation

What is the difference between Table Fragmentation & Tablespace Fragmentation.
What causes Table Fragmentation and what cause Tablespace Fragmentation.
How can we avoid Table Fragmentation & Tablespace Fragmentation.
How can we fix already Fragmented Tables & Fragmented Tablespaces
Thanks
Naveen

Unless you are using an exceptionally old version of Oracle or are still using dictionary managed tablespaces or are using some interesting definitions of "fragmentation", fragmentation is practically impossible in Oracle.
Justin

How we find tablespace fragmentation and resolve this problem

Hi,
How we find tablespace fragmentation and resolve this in 10 G (R2) windows XP.
Regards
Faheem

Hi,
>>Are you using Dictionary Managed or Locally Managed Tablespaces...??
In fact, there is no way to create a DMT if SYSTEM tablespace is LMT. So, what I said in my previous post "Unless the OP is using DMT ..." is impossible in Oracle 10g ...
SQL> create tablespace tbs_test
2 datafile '/u01/oradata/BDRPS/test01.dbf' size 5m
3 extent management dictionary;
create tablespace tbs_test
ERROR at line 1:
ORA-12913: Cannot create dictionary managed tablespace
SQL> select extent_management from dba_tablespaces
2 where tablespace_name='SYSTEM';
EXTENT_MAN
LOCALCheers
Legatti

Checking Tablespace Fragmentation...

Folks,
Can someone share a high-end script for Checking Tablespace Fragmentation that shows exact numbers/values?
The one I have shows only yes or no..
Pasting my script below:
Prompt Fragmentation Level in the db
Prompt
TTitle left "*** Fragmentation Level in the db (As of:"xdate ") from mtdb" skip2
SELECT dfsc.tablespace_name tablespace_name,
DECODE (
dfsc.percent_extents_coalesced,
100,
(DECODE (
GREATEST ((SELECT COUNT (1)
FROM dba_free_space dfs
WHERE dfs.tablespace_name = dfsc.tablespace_name),
1),
1,
'No Frag',
'Fragmented'
'Possible Honey Comb Frag'
fragmentation_status
FROM dba_free_space_coalesced dfsc
ORDER BY dfsc.tablespace_name
ttitle off
results:
TABLESPACE_NAME FRAGMENTATION_STATUS
IIS_TABS1 No Frag
IIS_TABS2 No Frag
IIS_TABS3 Fragmented
IIS_TABS4 No Frag
IIS_TABS5 No Frag
regards,
Lily

Can you explain what, exactly, you mean by "tablespace fragmentation"? Assuming you are on a recent version of Oracle and using locally managed tablespaces (LMT's), fragmentation in the sense of having a chunk of space on disk that cannot be reused because it is too small is all but impossible. Technically, it is still possible in a LMT with automatic rather than uniform extent allocation, but it is exceptionally difficult in practice to come up with such a scenario.
Tablespace fragmentation was a potential problem in long-ago days when there were dictionary-managed tablespaces (DMT's) when individual objects could have different extent allocation policies and PCTINCREASE could be specified. The solution back then was to set INITIAL = NEXT = <<some reasonable constant>> and PCTINCREASE = 0 and simulate the uniform extent allocation option of LMTs.
Justin

Best way to correct Tablespace fragmentation?

Dear DBAs,
The following query returns tablespace fragmentation:
select
tablespace_name,
count(*) free_chunks,
decode(
round((max(bytes) / 1024000),2),
null,0,
round((max(bytes) / 1024000),2)) largest_chunk,
nvl(round(sqrt(max(blocks)/sum(blocks))*(100/sqrt(sqrt(count(blocks)) )),2),
0) fragmentation_index
from
sys.dba_free_space
group by
tablespace_name
order by
2 desc, 1;
I have 3 tablespaces that are Locally Managed and suffer heavyt fragmentation. I just received the task of tuning this database and from what I could tell the fragmentation originated from a number of bad practices from past DBAs and also, some bizarre structures in certain tables.
My question is: what would be the best way to correct tablespace fragmentation LMT? I'm thinking export - drop - import to reorganize all blocks within the tablespace?

Alvaro wrote:
Dear DBAs,
The following query returns tablespace fragmentation:
select
tablespace_name,
count(*) free_chunks,
decode(
round((max(bytes) / 1024000),2),
null,0,
round((max(bytes) / 1024000),2)) largest_chunk,
nvl(round(sqrt(max(blocks)/sum(blocks))*(100/sqrt(sqrt(count(blocks)) )),2),
0) fragmentation_index
from
sys.dba_free_space
group by
tablespace_name
order by
2 desc, 1;
I have 3 tablespaces that are Locally Managed and suffer heavyt fragmentation. I just received the task of tuning this database and from what I could tell the fragmentation originated from a number of bad practices from past DBAs and also, some bizarre structures in certain tables.
My question is: what would be the best way to correct tablespace fragmentation LMT? I'm thinking export - drop - import to reorganize all blocks within the tablespace?In addition to what everyone else notes is the unlikelihood of fragmentation, there may be implicit compaction and skew in your data distribution that could be impacted by export/import. For better or worse.
What bad practices are you referring to? Sometimes practices are inappropriate, sometimes useless, sometimes perfectly understandable. If you don't know about the fragmentation issue, I wonder how well you judge practices. And yes, there are some really bad practices floating about.

What kind of fragmentation would you park this under ?

hi guys
i am reading about
alter table xxxx shrink command;
on http://www.oracle.com/technology/pub/articles/10gdba/week15_10gdba.html
q1) do you consider this as a fragmentation ?
q2) if so, what kind of fragmentation does this falls under ?
q3) o`reilly oracle essential park this under segment fragmentation
but to me. it seems to be some kind "blocks fragmentation" which i believe, those empty spaces will be reuse again due to further insert or updates and those empty spaces will be coaleces during the reuse of the freespace as state in the oracle concept
<i>Released space may or may not be contiguous with the main area of free space in a
data block. Oracle coalesces the free space of a data block only when (1) an INSERT or
UPDATE statement attempts to use a block that contains enough free space to contain a
new row piece, and (2) the free space is fragmented so the row piece cannot be
inserted in a contiguous section of the block. </i>
hope to hear advices from you guys soon.
Regards,
Noob

q1 no
q3 if it would qualify as fragmentation it is segment fragmentation.
But it's not fragmentation.
The article is poor and shouldn't have been posted on Oracle's website.
The author fails to differentiate between freelist managed tablespaces and ASSM tablespaces. In the latter case fragmentation is no longer an issue.
Also the author states alter table move should move to a new tablespace and can't be executed online.
Both are incorrect.
Finally the article omits one fundamental question: does suffering from Compulsive Reorganization Disorder solve fragmentation? Or is it just a waste of resources?
Sybrand Bakker
Senior Oracle DBA

Tablespace fragmentation

Hi All,
How can I identify the tablespace is fragmented or not?
If fragmented how can I resolve the issue while production database is up & running.
Thanks in advance...

REM     This script measures the fragmentation of free space
REM     in all of the tablespaces in the database and scores them
REM     according to an arbitrary index for comparison
REM
REM               largest extent     100
REM     FSFI = 100 * sqrt(------------------) * (-------------------------------)
REM               sum of all extents sqrt(sqrt((number of extents)))
REM
REM     FSFI - Free Space Fragmentation index
REM     The largest possible FSFI (for an ideal single-file tablespace) is 100
REM     As the number of extents increases, the FSFI rating drops slowly. As the size of
REM     the largest extent drops, however, the FSFI rating drops rapidly.
select          tablespace_name
, file_id
,          sqrt(max(blocks)/sum(blocks)) *
          (100/sqrt(sqrt(count(blocks)))) fsfi
from          dba_free_space
group by     tablespace_name, file_id
order by     1,2;
You can move object to another tablespace and rebuild the associated indexes for tablespace fragmentation.
Drop the old tablespace.
Also you can go for export/import.
Regards
Asif Kabir

Tablespace fragmentation problem

All,
I am working in Oracle 9i. Developers are facing some problem. Oracle is throwing ORA-1654 error. There is enough space in the tablespaces. To me it seems to be fragmentation problem. I found one query on some site and executed in my environment.
SQL> select substr(ts.name, 1,10) TableSpace,to_char(f.file#,990) "file #",tf.blocks blocks,sum(f.length) free,to_char(count(*),9990) frags,max(f.length) bigst, to_char(min(f.length),999990) smllst,round(avg(f.length)) avg,to_char(sum(decode(sign(f.length-5), -1, f.length,0)),99990) dead from sys.fet$ f, sys.file$ tf, sys.ts$ ts where ts.ts# = f.ts# and ts.ts# = tf.ts# group by ts.name, f.file#, tf.blocks;
TABLESPACE file BLOCKS FREE FRAGS BIGST SMLLST AVG DEAD
GAP_ARC 7 15360 8239 108 6099 20 76 0
GAP_BILD 8 256000 223804 3655 77909 5 61 0
GAP_DATA 9 230400 48267 211 3937 5 229 0
GAP_GEN 10 192000 86156 902 52178 1 96 3
GAP_IMP 11 38400 37669 14 37399 10 2691 0
GAP_INDEX 12 230400 96408 3557 506 1 27 5335
GAP_INDEX 12 409600 96408 3557 506 1 27 5335
GAP_INDEX 13 230400 56120 1611 495 2 35 2627
GAP_INDEX 13 409600 56120 1611 495 2 35 2627
GAP_ZNZL 14 1920 1919 50 515 10 38 0
RBS 3 51200 30479 871 35 29 35 0
RBS_BIG 4 76800 63929 157 43649 130 407 0
SYSTEM 1 25600 25952 2 12976 12976 12976 0
SYSTEM 2 25600 22728 20 11321 2 1136 12
TEMP 5 64000 58279 252 25649 130 231 0
TOOLS 6 6400 6384 1 6384 6384 6384 0
16 Zeilen ausgewählt.
From the output it seems GAP_INDEX has some fragmentation problem. Can somebody suggest, what the output means particularly the "DEAD" one.
And also, how to do the fragmentation ??
Thanks for help.
Regards,
Rajeev

I haven't taken the time to study the query in depth but I think 'dead' is an attempt to identify free exents that are too small to be used.
The original post leaves out some very important information such as the type of tablespace space allocation in use: dictionary vs local with auto-allocate or uniform extents.
As one poster noted if you use locally managed tablespaces wtih uniform extents then free space fragmentation by definition cannot exist.
With auto-allocate and dictionary mangement it can. Auto-allocate generally extents the time till a tablespace's free space becomes fragemented such that the space is not usuable and contains logic to reclaim via reuse but with the right combination of very small and very large objects the problem can still exist.
Dictionary management is almost bound to lead to free space fragmentation conditions for an active system though the adoption of a proper extent sizing policy can help: initial = next with pctincrease = 0 for all objects in a tablespace and the extent sizes for the larger objects being an even multiple of the small object extent size.
For auto-allocate and especially dictionary management when free space gets low the options are re-create the objects to consolidate all free space into a few large contiguous chunks or add another file. Sometimes you can relocate an object whose extents can then be reused by other objects. With uniform extents moving an object to another tablespace always creates fully reusable free space. Since objects should be where you want them the only real option then is to add free space is to add a file. Managing free space in a uniform extent environment then is genarally very straight forward.
HTH -- Mark D Powell --

Tablespace Fragmentation. specially in SYSTEM tablesapce.

Hi,
I am working on Oracle 11gR2 DB and AIX OS.
An database is having many tablespaces which are allocated to specific schemas. These schemas are functional from a long time. Data comes and goes all the time. The size of the tablespace has gone very high(than expected). We have removed(truncated) most of the unwanted tables and data from the schema and trying to resize the datafile, but we are not able to do it.
while checking with the below query :-
SELECT   df.tablespace_name "Tablespace",
       df.bytes / (1024 * 1024) "Size (MB)",
       SUM(fs.bytes) / (1024 * 1024) "Free (MB)",
       Nvl(Round(SUM(fs.bytes) * 100 / df.bytes),1) "% Free",
       Round((df.bytes - SUM(fs.bytes)) * 100 / df.bytes) "% Used"
FROM dba_free_space fs,
       (SELECT tablespace_name,SUM(bytes) bytes
          FROM dba_data_files
         GROUP BY tablespace_name) df
WHERE fs.tablespace_name (+) = df.tablespace_name
GROUP BY df.tablespace_name,df.bytes
UNION ALL
SELECT df.tablespace_name tspace,
       fs.bytes / (1024 * 1024),
       SUM(df.bytes_free) / (1024 * 1024),
       Nvl(Round((SUM(fs.bytes) - df.bytes_used) * 100 / fs.bytes), 1),
       Round((SUM(fs.bytes) - df.bytes_free) * 100 / fs.bytes)
FROM dba_temp_files fs,
       (SELECT tablespace_name,bytes_free,bytes_used
          FROM v$temp_space_header
         GROUP BY tablespace_name,bytes_free,bytes_used) df
WHERE fs.tablespace_name (+) = df.tablespace_name
GROUP BY df.tablespace_name,fs.bytes,df.bytes_free,df.bytes_used
ORDER BY 4 DESC;
The output is :-
tablespace name         size_MB    free_space_MB     %free %used
SYSTEM                34256     28941.375        84            16
   SMD                      7975     2991.1875        38            62
.................N many other Here if i try to resize the SMD tablespace datafile to (7975-2991.1875) 4983 MB it does not allow me to do it.
Also the SYSTEM tablespace has gone so big but used space is very less.
I suspect that fragmentation is the problem here._
Please guide me what could i do in these case to reduce the space taken by the datafiles.
Thanks in advance.

Thanks for notifying......I have a misconception about it...both the queries giving almost same result.
but first query give you result at datafile level.
SQL> column tablespace_name format a10
SQL> column file_name format a32
SQL> column file_mb format 9999990
SQL> column hwm_mb format 9999990
SQL> column used_mb format 9999990
SQL> column shrnk_mb format 9999990
SQL>
SQL> break on report
SQL> compute sum of file_mb on report
SQL> compute sum of hwm_mb on report
SQL> compute sum of used_mb on report
SQL> compute sum of shrnk_mb on report
SQL>
SQL> select a.*
2 , file_mb-hwm_mb shrnk_mb
3 from (
4 select /*+ rule */
5 a.tablespace_name,
6 a.file_name,
7 a.bytes/1024/1024 file_mb,
8 b.hwm*d.block_size/1024/1024 hwm_mb,
9 b.used*d.block_size/1024/1024 used_mb
10 from
11 dba_data_files a,
12 (select file_id,max(block_id+blocks-1) hwm,sum(blocks) used
13 from dba_extents
14 group by file_id) b,
15 dba_tablespaces d
16 where a.file_id = b.file_id
17 and a.tablespace_name = d.tablespace_name
18 ) a
19 order by a.tablespace_name,a.file_name;
TABLESPACE FILE_NAME                         FILE_MB   HWM_MB USED_MB SHRNK_MB
SYSAUX     C:\ORACLEXE\APP\ORACLE\ORADATA\X      710      673      672       37
           E\UNDOTBS1.DBF
SYSTEM     C:\ORACLEXE\APP\ORACLE\ORADATA\X      360      353      352        7
           E\SYSTEM.DBF
UNDOTBS1   C:\ORACLEXE\APP\ORACLE\ORADATA\X      260      258      257        2
           E\SYSAUX.DBF
USERS      C:\ORACLEXE\APP\ORACLE\ORADATA\X     6340     6017     6016      323
           E\USERS.DBF
TABLESPACE FILE_NAME                         FILE_MB   HWM_MB USED_MB SHRNK_MB
sum                                             7670     7301     7296      369
SQL> SELECT /* + RULE */ df.tablespace_name "Tablespace",
2         df.bytes / (1024 * 1024) "Size (MB)",
3         SUM(fs.bytes) / (1024 * 1024) "Free (MB)",
4         Nvl(Round(SUM(fs.bytes) * 100 / df.bytes),1) "% Free",
5         Round((df.bytes - SUM(fs.bytes)) * 100 / df.bytes) "% Used"
6    FROM dba_free_space fs,
7         (SELECT tablespace_name,SUM(bytes) bytes
8            FROM dba_data_files
9           GROUP BY tablespace_name) df
10   WHERE fs.tablespace_name (+) = df.tablespace_name
11   GROUP BY df.tablespace_name,df.bytes
12 UNION ALL
13 SELECT /* + RULE */ df.tablespace_name tspace,
14         fs.bytes / (1024 * 1024),
15         SUM(df.bytes_free) / (1024 * 1024),
16         Nvl(Round((SUM(fs.bytes) - df.bytes_used) * 100 / fs.bytes), 1),
17         Round((SUM(fs.bytes) - df.bytes_free) * 100 / fs.bytes)
18    FROM dba_temp_files fs,
19         (SELECT tablespace_name,bytes_free,bytes_used
20            FROM v$temp_space_header
21           GROUP BY tablespace_name,bytes_free,bytes_used) df
22   WHERE fs.tablespace_name (+) = df.tablespace_name
23   GROUP BY df.tablespace_name,fs.bytes,df.bytes_free,df.bytes_used
24   ORDER BY 4 DESC;
Tablespace                      Size (MB) Free (MB)     % Free     % Used
TEMP                                   20         17         85         15
USERS                                6340   323.3125          5         95
SYSAUX                                710      37.25          5         95
SYSTEM                                360     7.3125          2         98
UNDOTBS1                              260     1.8125          1         99
SQL>

Removing Tablespace fragmentation in 10g

i have a problem with a tablespace space that is highly fragmented . It's locally managed with PCT_INCREASE set to 0. How can i reduce the fragmentation in this tablepsace
Free/Used Space Report :
Tablespace                        Used MB    Free MB   Total MB Pct. Free
FRP_I01                            158556      44625     203181         22
select PCT_INCREASE,EXTENT_MANAGEMENT,SEGMENT_SPACE_MANAGEMENT from dba_tablespaces where TABLESPACE_NAME='FRP_I01';
PCT_INCREASE EXTENT_MAN SEGMEN
           0 LOCAL      AUTO
fragmentation report :
select
2 tablespace_name,
3 count(*) free_chunks,
decode(
4    5 round((max(bytes) / 1024000),2),
6 null,0,
7 round((max(bytes) / 1024000),2)) largest_chunk,
8 nvl(round(sqrt(max(blocks)/sum(blocks))*(100/sqrt(sqrt(count(blocks)) )),2),
9 0) fragmentation_index
10 from
11 sys.dba_free_space
12 group by tablespace_name
13 having tablespace_name='FRP_I01'
14 order by
15 2 desc, 1;
TABLESPACE_NAME                FREE_CHUNKS LARGEST_CHUNK FRAGMENTATION_INDEX
FRP_I01                                201         11904               13.56
SELECT   dfsc.tablespace_name tablespace_name,
2           DECODE (
3              dfsc.percent_extents_coalesced,
            100,
4    5              (DECODE (
6                  GREATEST ((SELECT COUNT (1)
7                               FROM dba_free_space dfs
8                              WHERE dfs.tablespace_name = dfsc.tablespace_name), 1),
9                  1,
10                  'No Frag',
11                  'Bubble Frag'
12               )
13              ),
14              'Possible Honey Comb Frag'
15           )
16                 fragmentation_status
17      FROM dba_free_space_coalesced dfsc
18 where dfsc.tablespace_name='FRP_I01'
19 ORDER BY dfsc.tablespace_name;
TABLESPACE_NAME                FRAGMENTATION_STATUS
FRP_I01                        Bubble Frag

yes, i know that. But as per my script this particular tablespace is fragmented and i want to know if some1 can help me out how to defragment it ?
A 100% score indicates no fragmentation at all. Lesser scores verify the presence of fragmentation.The free chunks count column will tell you how many segments of free space are scattered throughout the tablespace.
thanks in advance

What does ip fragment reassembly do

hi can someone pls tell me what is the meaning of ip reassembly mode in the global configuration where it gives a option for operating system.
i mean what does this option actually do.
can someone pls guide me.
regards
sebastan

When a datagram is fragmented by normal methods there is never any fragment overlap or overwrite. Where one fragment ends, the next fragment begins at the very next bit. And all operating system assemble these fragments exactly the same.
But fragments can and some times do overlap. One fragment might end at say byte 1400. The next fragment should begin at byte 1401, but on occasion you will have an overlap where that next fragment begins at byte 1399 or earlier. So long as both fragments have the exact same data for those bytes that overlap, then the packet will still be reassembled the same by all operating systems.
BUT if the 2 fragments have DIFFERENT data for that same area of the reassembled datagram, then we call this an overwrite. And each operating system can have a different way with how it deals with the overwrites and chooses which data to accept.
Say for example that the first fragment ended at byte 1400 and had "ab" at bytes 1399 and 1400.
The next fragment is an overwrite and begins and byte 1399 and has "xy" at bytes 1399 and 1400.
One operating system will reassemble these and end up with "ab", while another will reassemble and up with "xy".
Each operating system has their own method of determining whether it will be "ab" or "xy".
In fact there are about 8 different ways that these packets can be reassemmbled depending on how they were sent, how they overlap, and their offset order.
Hackers understand this and will use it to attempt to evade the sensor.
The hacker will determine the operating system of the end host and will then try to send his attack in such away so that the end host will see it as "ab" and get hacked, but the sensor reassemble it as "xy" and thinks there is nothing wrong.
It would be great if the sensor could reassemble the fragments and analyze them in ever one of the 8 possible ways that operating systems can reassemble them.
But this is too cpu and memory intensive for the sensor to be able to handle.
So instead of trying all 8 possibilities the users chooses the operating system that is the most common in their network. The sensor will then reassemble the fragments in the same method as that operating system.
Understand that this ONLY applies to Fragment OverWrites.
For normal fragments where one fragment ends and the next begins, and for fragment Overlaps where both fragments have the same data; this setting doesn't matter because all operating system will reassembly them the same way.
So if you are concerned about this, then you need to monitor for the fragment OverWrite alarm.
The operating system configuration only comes into play when the fragments OverWrite one another, and you will see the fragment OverWrite alarm being triggered.

What's tablespace doing if I create user?

I want create a new user with the same privileges of a DBA in my database.
But I must enter ...
- DEFAULT TABLESPACE
- TEMPORARY TABLESPACE
What's the Talespace function? if is not to long to explain ;)
null

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Andrew Jones:
Specifying a default tablespace for a user means that any objects they create (tables, views, etc.) will reside in the specified tablespace, rather than the SYSTEM tablespace, which is where the object would wind up otherwise. Note that this doesn't apply to server-side PL/SQL such as packages and procedures, which are always created in SYSTEM. If you want an object to be created in another tablespace than the default for the user, use the TABLESPACE specifier with your CREATE statement.
Hope this clears it up (slightly!).<HR></BLOCKQUOTE>
Yes...thank's a lot!
null

What is best fragmentation software?

My MacBook Pro with 2Gs RAM and 160G HD has been running very slow, particularly if I have several Safari windows open. I have 37G space available on my 160G HD. In addition to dumping excess files to free up more space on my HD, would a de-fragmentation software program help?

It could mess things up even worse.
You likely have other issues, 37GB of free space on 160GB is considerable, about 24% which is about when it starts slowing down. So you could remove some files to a external drive that your not using, or may decide to upgrade to a 7,200 RPM drive and more RAM to max out your machines performance.
Lets try something first, you might not have to resort to a full backup, Zero Erase and fresh install of OS X, but that certianly would do the trick much safer than a defragmentation software.
This is going to check out the drive, clean somethings out and perhaps reveal some other issues if they exist or not.
Download the free OnyX and run All the initial checks, maintenance and finally cleaning steps and reboot at the end (you can cancel the in between reboots)
http://www.macupdate.com/app/mac/11582/onyx
You need to download your OS X verison to match. Make sure to enable "all accounts" in OnyX preferences.
Also if it gives any warning, quit and backup your files off the machine as soon as possible and report back here.
Machine may act a bit slower upon reboot, then it should scream, I think you may have a corrupt Safari cache file.

How to find Fragmentation of tables and tablespaces in oracle 8i

Hi,
How can i measure the fragmentation of Tables and Tablespaces in oracle 8i.
Do any one have any handy script to find the same.
What are the attributes to be determined to do health checkup of a database.

how many such empty blocks are there in the table and of what size.Again Tom Kyte reference :
http://asktom.oracle.com/pls/ask/f?p=4950:8:7760471022221195640::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:231414051079
For tablespace, fragmentation is the regular termAbout tablespace, the link from post above can help.
Nicolas.

How to find a tablespace is fragmented or not?

Hi,
I was aksed to find wether a tablespace is fragmented or not. if fragmented i need to relase the fragmented space. Can any body has solution for the same.
Regards
DBA.

1) What do you believe this query shows?
2) How do you define "bubble fragmentation" and "honeycomb fragmentation"?
3) Why (and when) do you believe a DBA would act to solve either problem?
4) Since your script is identifying tablespaces, how would you propose determining which objects in your estimation need to be rebuilt?
5) How have the answer to these questions changed since the move to locally managed tablespaces a decade ago?
Back in the old days of dictionary managed tablespaces, fragmentation was a real thing that DBAs had to keep track of because every table was potentially allocating differently sized extents in a tablespace, there were lots of odd extent sizes, and it was relatively easy to end up with free space in a data file that no object in the tablespace could ever use because it was smaller than the next extent size of the objects. That is no longer a concern with locally managed tablespace-- it is not (practically) possible to have (a reasonable quantity) of disk space that is free but unusable in a locally managed tablespace, particularly when you are using uniform extents.
Justin

What is tablespace fragmentation?

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