Patent · US Expired

Database system with methods for improving query performance with cache optimization strategies

US5822749A · kind A · utility

253Cited by
5References
25Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 28, 1997
Grant dateOct 13, 1998
Priority date
Expiry dateFeb 28, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S707/99933
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Database system and methods are described for improving execution speed of database queries (e.g., for transaction processing and for decision support) by optimizing use of buffer caches. The system includes an Optimizer for formulating an optimal strategy for a given query. More particularly, the Optimizer communicates with a Buffer Manager before it formulates the query plan. For instance, the Optimizer may query the Buffer Manager for the purpose of determining whether the object of interest (e.g., table or index to be scanned) exists in its own buffer cache (i.e., whether it has been bound to a particular named cache). If the object exists in its own cache, the Optimizer may inquire as to how much of the cache (i.e., how much memory) the object requires, together with the optimal I/O size for the cache (e.g., 16K blocks). Based on this information, the Optimizer formulates a query strategy or plan with "hints," which are ultimately passed to the Cache or Buffer Manager. By formulating "hints" for the Buffer Manager at the level of the Optimizer, knowledge of the query is, in effect, passed down to the Buffer Manager so that it may service the query using an optimal caching stra…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.