Chengliang N Zhang

US Patent:

8352684, Jan 8, 2013

Filed:

Sep 23, 2008

Appl. No.:

12/236188

Inventors:

Roch Georges Archambault - North York, CA
Shimin Cui - Toronto, CA
Chen Ding - Rochester NY, US
Yaoqing Gao - North York, CA
Xiaoming Gu - Handan, CN
Raul Esteban Silvera - Woodbridge, CA
Chengliang Zhang - Redmond WA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G06F 12/00

US Classification:

711133, 711136, 711159

Abstract:

Computer implemented method, system and computer usable program code for cache management. A cache is provided, wherein the cache is viewed as a sorted array of data elements, wherein a top position of the array is a most recently used position of the array and a bottom position of the array is a least recently used position of the array. A memory access sequence is provided, and a training operation is performed with respect to a memory access of the memory access sequence to determine a type of memory access operation to be performed with respect to the memory access. Responsive to a result of the training operation, a cache replacement operation is performed using the determined memory access operation with respect to the memory access.

US Patent:

20110219169, Sep 8, 2011

Filed:

Mar 4, 2010

Appl. No.:

12/717139

Inventors:

Chengliang Zhang - Redmond WA, US
Sadashivan krishnamurthy - Redmond WA, US
Georgiy I. Reynya - Redmond WA, US
Alexandre Verbitski - Woodinville WA, US

Assignee:

Microsoft Corporation - Redmond WA

International Classification:

G06F 12/00
G06F 12/02
G06F 17/00

US Classification:

711103, 711159, 707609, 707E17005, 711E12001, 711E12008

Abstract:

Aspects of the subject matter described herein relate to a buffer pool for a database system. In aspects, secondary memory such as solid state storage is used to extend the buffer pool of a database system. Thresholds such as hot, warm, and cold for classifying pages based on access history of the pages may be determined via a sampling algorithm. When a database system needs to free space in a buffer pool in main memory, a page may be evicted to the buffer pool in secondary memory or other storage based on how the page is classified and conditions of the secondary memory or other storage.

US Patent:

20120072652, Mar 22, 2012

Filed:

Nov 28, 2011

Appl. No.:

13/305670

Inventors:

Pedro Celis - Redmond WA, US
Dexter Paul Bradshaw - Duvall WA, US
Sadashivan Krishnamurthy - Redmond WA, US
Georgiy I. Reynya - Redmond WA, US
Chengliang Zhang - Sammamish WA, US
Hanumantha Rao Kodavalla - Sammamish WA, US

Assignee:

MICROSOFT CORPORATION - Redmond WA

International Classification:

G06F 12/00

US Classification:

711103, 711159, 711105, 711E12008

Abstract:

A buffer manager that manages blocks of memory amongst multiple levels of buffer pools. For instance, there may be a first level buffer pool for blocks in first level memory, and a second level buffer pool for blocks in second level memory. The first level buffer pool evicts blocks to the second level buffer pool if the blocks are not used above a first threshold level. The second level buffer pool evicts blocks to a yet lower level if they have not used above a second threshold level. The first level memory may be dynamic random access memory, whereas the second level memory may be storage class memory, such as a solid state disk. By using such a storage class memory, the working block set of the buffer manager may be increased without resorting to lower efficiency random block access from yet lower level memory such as disk.