12c with Inmemory gives slower performance on a query

Hi,

Playing around with the new 12.1.0.2 release on RHEL6 I have a quite heavy query that actually runs faster when not using Inmemory.

This is the database:

inmemory_clause_default                             string

inmemory_force                                           string      DEFAULT

inmemory_max_populate_servers                  integer     12

inmemory_query                                                string      ENABLE

inmemory_size                                                 big integer 60G

inmemory_trickle_repopulate_servers_ integer     1

percent

memory_max_target                    big integer 110G

memory_target                        big integer 110G

This is the query:

  SELECT MDV_TIME_DAY_RTL.WK_SHRT_NAME,

  DDW.MDV_SALE_ITM.RTN_RSN_CODE,

  DDW.MDV_LOC_MRKT.MRKT_DSPL_NAME,

  DDW.MDV_LOC_STOR.STOR_DSPL_NAME,

  DDW.MDV_PROD_BA.BA_DSPL_NAME,