1 Reply Latest reply on May 9, 2012 9:36 AM by dm_ptldba

    Import of LOB table occupying more space on target database

    dm_ptldba
      Hello,

      source database -- RAC 10gR2 (On Linux 3 - 32 bit)
      target database -- RAC 11gR2 (On Linux 5 -64 bit)

      Need your help on this. -- Today i did a import of 104 gig schema which has a lob in one of the table. Strange thing is in source database(10g version) size of lob table is 104 gig and in target(11g version) after import the size is 207 gig. Not sure why 100 gig more is occupied in target,

      can some you please have a look on it, let me know if you need further details for this...

      Thanks,
      Tanveer Mohammed.
        • 1. Re: Import of LOB table occupying more space on target database
          dm_ptldba
          Hi,

          Did not get any reply from OTN forums, i found the solution from Oracle. This happen as we are moving from one character set to other


          SOURCE (export):
          PARAMETER VALUE
          ------------------------------ ----------------------------------------
          NLS_CHARACTERSET US7ASCII
          NLS_NCHAR_CHARACTERSET AL16UTF16


          TARGET (import):
          PARAMETER VALUE
          ------------------------------ ----------------------------------------
          NLS_CHARACTERSET AL32UTF8
          NLS_NCHAR_CHARACTERSET AL16UTF16


          AL32UTF8 / UTF8 (Unicode) Database Character Set Implications (Doc ID 788156.1)

          The biggest expansion will be seen with CLOB's, if the source database is a 8 bit characterset (WE8ISO8859P1, WE8MSWIN1252 etc) then populated Clob columns will double in disksize.Note 257772.1 CLOBs and NCLOBs character set storage in Oracle Release 8i, 9i and 10g

          An Estimation of the expansion is listed in the Csscan .txt file output under the Expansion header. See Note 444701.1 Csscan output explained
          We advice to use Csscan always when going to AL32UTF8, see point B.5).

          Thanks,
          Tanveer Mohammed