Replay time: 56:53
SQL to identify Candidate tablespaces that are very large compared to other tablespaces:

# Please modify this as your needs demand.
with
   temp1 as
    (select TBSP_NAME as tbsp_name, sum(TBSP_USED_SIZE_KB/1024) as tbsp_size
       from sysibmadm.tbsp_utilization
group by TBSP_NAME) ,
  temp2 as
    (select t1.tbspace as tbsp_name, count(*) as tbl_cnt
          from syscat.tables t1, syscat.tablespaces t2
                where t1.type='T‘ and t1.tbspace=t2.tbspace
                        and t1.tbspace <> 'DWEDEFAULTCONTROL'
                group by t1.tbspace
                 having count(*) > 1)
    select char(temp1.TBSP_NAME,20),  temp1.tbsp_size, temp2.tbl_cnt
      from temp1, temp2 where temp1.tbsp_name=temp2.tbsp_name
order by temp1.tbsp_size desc fetch first 100 rows only with ur
;

Replay time: 57:47

SQL1 -- Identify tablespaces with > 1 GB HWM reduction opportunity:
SELECT CHAR(TBSP_NAME,18) AS TBSP_NAME,
   SUM((TBSP_PAGE_TOP-TBSP_USED_PAGES)*TBSP_PAGE_SIZE/1024/1024/1024) as TO_BE_REDUCED_SPACE_GB
    FROM SYSIBMADM.TBSP_UTILIZATION
    GROUP BY TBSP_NAME
    HAVING SUM((TBSP_PAGE_TOP-TBSP_USED_PAGES)*TBSP_PAGE_SIZE/1024/1024/1024) > 1
     ORDER BY 2 DESC
     FETCH FIRST 100 ROWS ONLY WITH UR;

SQL 2 – Identify how much space (MB) would be reduced from each container:
(if you are curious to find out how much HWM in MB would be reduced by DB2)

SELECT
     char(TBSP_UTIL.TBSP_NAME,20) AS TABLESPACE,
     char(CONTAINER_NAME,50) as CONTAINER,
     TBSP_UTIL.DBPARTITIONNUM as PARTITION,
     TBSP_PAGE_TOP                       as HWM,
     (TBSP_FREE_SIZE_KB/1024)            as FREE_MB,
     (TBSP_PAGE_TOP-TBSP_USED_PAGES)*TBSP_PAGE_SIZE/1024/1024 as HWM_REDUCTION_OPPORTUNITY_MB

from SYSIBMADM.TBSP_UTILIZATION TBSP_UTIL,
      SYSIBMADM.CONTAINER_UTILIZATION CONT_UTIL
WHERE TBSP_UTIL.TBSP_NAME=CONT_UTIL.TBSP_NAME AND
      TBSP_UTIL.DBPARTITIONNUM=CONT_UTIL.DBPARTITIONNUM
AND
TBSP_UTIL.TBSP_NAME=‘$TBSP’ order by TBSP_UTIL.DBPARTITIONNUM with ur;

Replay time: 58:20
Information to help fix skew at table level:

URL: http://www.ibm.com/developerworks/data/library/techarticle/dm-1005partitioningkeys/
Example from IBM Info Center:
$db2 "set serveroutput on" 
$ db2 "CALL estimate_existing_data_skew('TPCD', 'SUPPLIER', 25)" 
CALL estimate_existing_data_skew('TPCD', 'SUPPLIER', 25) 
Return Status = 0 
DATA SKEW ESTIMATION REPORT FOR TABLE: TPCD.SUPPLIER 
Accuracy is based on 25% sample of data 
------------------------------------------------------------------------ 
TPCD.SUPPLIER 
Estimated total number of records in the table: : 19,994,960 
Estimated average number of records per partition : 2,499,368 
Row count at partition 1 : 1,599,376 (Skew: -36.00%) 
Row count at partition 2 : 2,402,472 (Skew: 3.87%) 
Row count at partition 3 : 4,001,716 (Skew: 60.10%) 
Row count at partition 4 : 2,394,468 (Skew: -4.19%) 
Row count at partition 5 : 1,600,028 (Skew: -35.98%) 
Row count at partition 6 : 1,599,296 (Skew: -36.01%) 
Row count at partition 7 : 2,397,116 (Skew: -4.09%) 
Row count at partition 8 : 4,000,488 (Skew: 60.05%) 
Number of partitions: 8 (1, 2, 3, 4, 5, 6, 7, 8) 
------------------------------------------------------------------------ 
Total execution time: 20 seconds