inmemory_area storage ENABLE_DDL_LOGGING conflict change database name imcu FBI optimization paging columnar nid pagination online patch 조나단루이스 backup inmemory_size USER_IND_EXPRESSIONS parameter rollback bp psu install ddl compression patch asktom hybrid index 설치 oracle recover rac 12c memory database replay flashback recommendation 11.2.0.4 V$EVENT_NAME rownum in-memory