Is there access control for CouchDB databases like PostgreSQL and MySQL privilege management?
Absolutely, you can set up users in the _users database. You can assign roles, groups, as well as any other custom fields for each user. In the validate_doc_update function in your design document(s), you can check user roles and approve or deny access based on that. You can also globally assign users as "readers" and "writers". You can authenticate users via Basic HTTP Authentication, OAuth and a variety of other methods.
Refer to the Security Features Overview and Document Update Validation pages on the wiki to get started.