Aggressive adaption algorithm for selective record caching
US5649153A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1995 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Jun 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0862
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A cache management system for dynamically switching between record caching and track caching. Statistics are collected within the cache management system to determine the type and amount of locality associated with a specific data set currently within the cache. Using these statistics, metrics of the actual hit ratio, whole-track hit ratio, and other-record-hit ratio are generated. The metrics are periodically reviewed for a given band, and the band is placed into one of three cache modes accordingly. The mode assignment determines what type of staging will be performed for data within the band in the event of a miss. The possible modes are: track mode for track-based staging, record mode for staging of a single record only, or uncached mode if no data is to be staged. If a band has been assigned to either record or track mode, the assignment is re-evaluated after for a predetermined number of I/O's (128). If the band has been assigned to uncached mode, then after another predetermined number of I/O's (4096), the band is reassigned to record mode in order to force an update of the band statistics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.