Shure DDLs generate redo information - if this was not true the recovery would not be possible. However they do not generate undo entries in the rollback segments - hence the rollback of DDL is not possible.
All DDLs are safely transfered over to the standby database, don't wory. Only if you change the physical layout of the primary database (add tablespace, add datafile) you have to transport this new datafiles to the standby before you apply the logs with those changes (you don't have to rebuild standby database at all!).
HTH,
Jurij Modic
ASCII a stupid question, get a stupid ANSI
24 hours in a day .... 24 beer in a case .... coincidence?