Using Disk Cache Facilities to Traverse an Index Tree Entirely Within the Disk Subsystem Containing an Indexed Data Set
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
This article discusses the use of an indexing technique for computer systems using disk cache memory. Described is a method of traversing an index tree to reduce channel activity and central processing time when fetching indexed data. The basic elements of the disk subsystem, as shown in Fig. 1, include the disk cache buffer 11 and the various levels of the index data base 12, the microprocessor 13 which is used to control all logical processing associated with interpretation of information from one level of index, then issuing the read operation to fetch information from the next index level. Also included is the disk Volume Table of Contents (VTOC) 14 which is maintained in microprocessor storage 15. A typical three-level tree format index structure, as shown in Fig.