You can update the retention period for any existing namespace other than the default namespace. It can take up to five minutes for a new retention policy to apply. The new retention period only applies to data added or updated in the namespace after this operation is complete. The retention period of existing data remains unchanged from the old retention period. Once you perform this operation you can't query the previously existing data. If you want to ensure that all data in the namespace has the same retention period you need to update the entire data set once the retention period has been updated. To change the access group used to authorize permission to a namespace, see Reauthorize a namespace. If you try to run this operation to update the access group, you get a 400 error.
Update namespace details