Script to Detect Tablespace Fragmentation

create table SPACE_TEMP (
 TABLESPACE_NAME        CHAR(30),
 CONTIGUOUS_BYTES       NUMBER)
/

declare
  cursor query is select *
          from dba_free_space
                  order by tablespace_name, block_id;
  this_row        query%rowtype;
  previous_row    query%rowtype;
total           number;

begin
  open query;
  fetch query into this_row;
  previous_row := this_row;
  total := previous_row.bytes;
  loop
 fetch query into this_row;
     exit when query%notfound;
     if this_row.block_id = previous_row.block_id + previous_row.blocks then
        total := total + this_row.bytes;
        insert into SPACE_TEMP (tablespace_name)
                  values (previous_row.tablespace_name);
     else
        insert into SPACE_TEMP values (previous_row.tablespace_name,
               total);
        total := this_row.bytes;
     end if;
previous_row := this_row;
  end loop;
  insert into SPACE_TEMP values (previous_row.tablespace_name,
                           total);
end;
.
/

set pagesize 60
set newpage 0
set echo off
ttitle center 'Contiguous Extents Report'  skip 3
break on "TABLESPACE NAME" skip page duplicate
spool contig_free_space.lis
rem
column "CONTIGUOUS BYTES"       format 999,999,999,999
column "COUNT"                  format 999
column "TOTAL BYTES"            format 999,999,999,999
column "TODAY"   noprint new_value new_today format a1
rem
select TABLESPACE_NAME  "TABLESPACE NAME",
       CONTIGUOUS_BYTES "CONTIGUOUS BYTES"
from SPACE_TEMP
where CONTIGUOUS_BYTES is not null
order by TABLESPACE_NAME, CONTIGUOUS_BYTES desc;

select tablespace_name, count(*) "# OF EXTENTS",
         sum(contiguous_bytes) "TOTAL BYTES"
from space_temp
group by tablespace_name;

spool off

drop table SPACE_TEMP
/

example output:

SQL> @TFSTSFRM

Table created.

PL/SQL procedure successfully completed.

                            Contiguous Extents Report

TABLESPACE NAME                CONTIGUOUS BYTES
------------------------------ ----------------
EXAMPLE                              32,768,000

                            Contiguous Extents Report

TABLESPACE NAME                CONTIGUOUS BYTES
------------------------------ ----------------
SYSAUX                                3,211,264

                            Contiguous Extents Report

TABLESPACE NAME                CONTIGUOUS BYTES
------------------------------ ----------------
SYSTEM                              371,130,368
SYSTEM                                  393,216

                            Contiguous Extents Report

TABLESPACE NAME                CONTIGUOUS BYTES
------------------------------ ----------------
UNDOTBS1                             13,500,416
UNDOTBS1                                524,288
UNDOTBS1                                458,752
UNDOTBS1                                458,752
UNDOTBS1                                327,680
UNDOTBS1                                262,144
UNDOTBS1                                196,608
UNDOTBS1                                131,072
UNDOTBS1                                131,072
UNDOTBS1                                131,072
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536
UNDOTBS1                                 65,536

                            Contiguous Extents Report

TABLESPACE NAME                CONTIGUOUS BYTES
------------------------------ ----------------
USERS                            10,995,367,936
USERS                                 1,048,576
USERS                                   393,216
USERS                                   262,144
USERS                                   196,608

26 rows selected.

                            Contiguous Extents Report

TABLESPACE_NAME                # OF EXTENTS      TOTAL BYTES
------------------------------ ------------ ----------------
EXAMPLE                                   1       32,768,000
UNDOTBS1                                 17       16,580,608
USERS                                     7   10,997,268,480
SYSAUX                                    1        3,211,264
SYSTEM                                    2      371,523,584

Table dropped.