5 Replies Latest reply: Jul 15, 2014 10:59 AM by Richard Harrison . RSS

    expdp compression=ALL generates quite a bit of redo

    9ef19b33-4f4c-4aea-a609-b9bdd74b76d0

      I am on 11.2.0.3.10 on linux 64bit.  We have started to use compression=ALL in expdp to save disk space.  I notice that during the export there is quite a bit of log switches/archive log generation.

      There is nothing else going on during the export.   In one database, we turned minimal supplemental logging on to use log miner to look in the archive log.  We see inserts into "UNKOWN".OBJ#xxxx.  The object reference number does not correspond to anything.  I am assuming that the redo is due to compression=ALL.  

      I found this note in oracle support: COMPRESS FOR ALL OPERATIONS generates lot of redo (Doc ID 829068.1).

      The article  is not specifically related to expdp, but it looks similar.

       

      The database is about 140GB, the redo logs are 50M each and the database is very quiet.  

      the expdp command:

      full=Y directory=DATAPUMP_DIR compression=ALL reuse_dumpfiles=y dumpfile=fullexport.dmp logfile=explog.log job_name=exportall

       

      Do any of you have similiar experiences with expdp compress=ALL?

       

      thank you!