the number of files after merging

[patcharee]

Hi,

I am using alter command below to merge partitioned orc file on one 
partition:

alter table X partition(zone=1,z=1,year=2009,month=1) CONCATENATE;

- How can I control the number of files after merging? I would like to 
get only one file per partition.
- Is it possible to concatenate the whole table, not one-by-one partition?

Thanks,
Patcharee