US Patent 9268806 Efficient reference counting in content addressable storage

According to some implementations, a method of managing database storage is performed for a database storage system having content storage, a content index, and a reference table. The content index identifies content chunks and the reference table stores references to each content chunk. An object is received for storage, which comprises one or more content chunks. The object is identified by a unique object ID. For each content chunk, the method constructs a content hash of the content chunk and looks up the content hash in the content index. When the content hash is not found in the content index, the method stores the content chunk in the content storage and inserts a record into the content index that identifies the location of the content chunk in the content storage. In addition, the method inserts a record into the reference table, which includes the content hash and the object ID.