Disabling auto compaction in CouchDB
You can find the description for how to configure automatic compaction in section 3.7 of the documentation. The basic info regarding the configuration of CouchDB can be found in section 3.1.

As I have never turned of automatic compaction and am not sure why you want this, I think you can play around with the settings to achieve it. There is no attribute to set automatic compaction to false. 

A word of warning: the basic principle of revisions (_rev) in CouchDB is to keep copies of documents for each revision. That means if you have a document sized 100 kb you will consume n * 100 kb disc space where n is the number of revisions. Please keep that in mind and be aware, that with many documents and many changes, your disk will be full very quickly.