Cached views

US10061808B2 · kind B2 · utility

Assignee

• SAP SE · DE

Inventors

• Ki Hong Kim · Seoul, KR
• Norman May · Karlsruhe, DE
• Alexander Boehm · Sandhausen, DE
• Sung Heun Wi · Opo-eup, KR
• Jeong A Han · Ansan-si, KR
• Sang Il Song · Kirkland, US
• Yongsik Yoon · Seoul, KR

Key dates

• Filing date: Jun 3, 2014
• Grant date: Aug 28, 2018
• Expiry date: Feb 13, 2036

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F16/2445
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Embodiments relate to view caching techniques that cache for a limited time, some of the (intermediate) results of a previous query execution, in order to avoid expensive re-computation of query results. Particular embodiments may utilize a cache manager to determine whether information relevant to a subsequent user request can be satisfied by an existing cache instance or view, or whether creation of an additional cache instance is appropriate. At design time, cache defining columns of a view are defined, with user input parameters automatically being cache defining. Cache instances are created for each tuple of literals for the cache defining columns, and for each explicit or implicit group by clause. Certain embodiments may feature enhanced reuse between cache instances, in order to limit memory footprint. Over time a cache instances may be evicted from memory based upon implementation of a policy such as a Least Recently Used (LRU) strategy.