Update Method for Write-Once Disk
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
A method is described for updating a single data record on write-once storage. Updates are written in sequential order, but are provided with an index that permits rapid retrieval of the current entry or the entry as of a specified time. The number of operations required for retrieval is logarithmic (to base larger than 2) in the number of updates as of the specified query time. One application of such a structure is in keeping track of the location of the root of a B-tree-like index to a data base. Another application is to keeping track of the location of the first free data track on a write-once disk. Storage space on a write-once disk comprises multiple tracks, each partitioned in writeable sectors.