Tables with MLPPI requires much more space than the same one with PPI - why? - forum topic by dagen

Hello all,
we hav a large table (CDRs) with PPI defined on timestamp containing date & time when a record was loaded in DW.

CREATE SET TABLE CZ_PRD_TGT.AMAOUT_NA ,NO FALLBACK ,
     NO BEFORE JOURNAL,
     NO AFTER JOURNAL,
     CHECKSUM = DEFAULT,
     DEFAULT MERGEBLOCKRATIO
     (
      AMAOUT_NA_ID VARCHAR(60) CHARACTER SET LATIN NOT CASESPECIFIC TITLE 'Amaout Network Activity Id' NOT NULL,
      REC_NUM_SEQ INTEGER TITLE 'Record Number Seq' NOT NULL,
      
      ...................... /* large number of columns here, not importat right now */

      LOAD_DTTM TIMESTAMP(6) TITLE 'Load Dttm' NOT NULL,
      HIST_TYPE INTEGER TITLE 'Historization Type' NOT NULL COMPRESS 990000005 )

PRIMARY INDEX AMAOUT_NA_NUPI_PPI ( AMAOUT_NA_ID )

PARTITION BY RANGE_N(CAST((ACTV_START_DTTM ) AS DATE AT TIME ZONE 'Europe Central')
                  BETWEEN DATE '2013-02-01' AND DATE '2013-09-30' EACH INTERVAL '1' DAY , NO RANGE, UNKNOWN);

However, because of a clear business requirement, multiple level partitionning would be much better - i.e. first level of partition should be the business validity of a record and the second level the should be the date & time when the records were loaded in DW:

CREATE SET TABLE CZ_PRD_MNC.AMAOUT_NA ,NO FALLBACK ,
     NO BEFORE JOURNAL,
     NO AFTER JOURNAL,
     CHECKSUM = DEFAULT,
     DEFAULT MERGEBLOCKRATIO
     (
      AMAOUT_NA_ID VARCHAR(50) CHARACTER SET LATIN NOT CASESPECIFIC TITLE 'Amaout Network Activity Id' NOT NULL,
      REC_NUM_SEQ INTEGER TITLE 'Record Number Seq' NOT NULL,

       ...................... /* large number of columns here, not importat right now */

      LOAD_DTTM TIMESTAMP(6) TITLE 'Load Dttm' NOT NULL,
      HIST_TYPE INTEGER TITLE 'Historization Type' NOT NULL COMPRESS 990000005 )

PRIMARY INDEX AMAOUT_NA_NUPI_MLPPI ( AMAOUT_NA_ID )

PARTITION BY ( RANGE_N(CAST((ACTV_START_DTTM ) AS DATE AT TIME ZONE 'Europe Central') 
                    BETWEEN DATE '2013-02-01' AND DATE '2013-09-30' EACH INTERVAL '1' DAY , NO RANGE, UNKNOWN),
               RANGE_N(CAST((LOAD_DTTM ) AS DATE AT TIME ZONE 'Europe Central')
                    BETWEEN DATE '2013-02-01' AND DATE '2013-09-30' EACH INTERVAL '1' DAY ,NO RANGE, UNKNOWN) );

What we found was that the volume of table with MLPPI was remarkably higher - original table had ~ 1TB, the new table with MLPPI has ~1,3 TB!
Does anybony know what is the reason that MLPPI requires so much higher disk space?
 
Thanks to all in advance
Dag