公开(公告)号：US09558221B2

公开(公告)日：2017-01-31

申请号：US14079060

申请日：2013-11-13

Applicant: Joseph Weizhen Hu ,  Mei-Lin Lin ,  Blaine C. French

Inventor： Joseph Weizhen Hu ,  Mei-Lin Lin ,  Blaine C. French

IPC: G06F7/00 ,  G06F17/30 ,  G06F13/14

CPC classification number: G06F17/30312

Abstract: Multi-pass parallel merging in a database includes identifying characteristics of non-final pages during database query operations. A phase of page consolidation is triggered based on the identified characteristics and a final page is stored.

Abstract translation: 数据库中的多遍并行合并包括在数据库查询操作期间识别非最终页面的特征。 基于所识别的特征触发页面合并阶段，并存储最终页面。

公开(公告)号：US20150134678A1

公开(公告)日：2015-05-14

申请号：US14079060

申请日：2013-11-13

Applicant: Joseph W. HU ,  Mei-Lin LIN ,  Blaine C. FRENCH

Inventor： Joseph W. HU ,  Mei-Lin LIN ,  Blaine C. FRENCH

IPC: G06F17/30

CPC classification number: G06F17/30312

Abstract: Multi-pass parallel merging in a database includes identifying characteristics of non-final pages during database query operations. A phase of page consolidation is triggered based on the identified characteristics and a final page is stored.

Abstract translation: 数据库中的多遍并行合并包括在数据库查询操作期间识别非最终页面的特征。 基于所识别的特征触发页面合并阶段，并存储最终页面。

公开(公告)号：US09262415B2

公开(公告)日：2016-02-16

申请号：US14075577

申请日：2013-11-08

Applicant: Mei-Lin Lin ,  Blaine French

Inventor： Mei-Lin Lin ,  Blaine French

IPC: G06F12/08 ,  G06F17/30

CPC classification number: G06F17/30 ,  G06F12/0815 ,  G06F12/0866 ,  G06F17/30306 ,  G06F2212/283

Abstract: Disclosed herein are system, method, and computer program product embodiments for storing and accessing data in a shared disk database system using a timestamp range to improve cache efficiency. An embodiment operates by retrieving, by a node, from a shared storage. a blockmap identity and a root page associated with a data request, based on a determination that the blockmap identity associated with a data request is present in a cache. The embodiment continues, retrieving, by the node, the logical page by copying a stored logical page from the shared storage and setting a lower timestamp value of the logical page to a timestamp associated with the stored logical page and an upper timestamp value of the logical page to a timestamp associated with the data request, based on a determination that the logical page is not present in the cache.

Abstract translation: 这里公开了用于使用时间戳范围来存储和访问共享磁盘数据库系统中的数据以提高高速缓存效率的系统，方法和计算机程序产品实施例。 实施例通过从节点检索共享存储器来进行操作。 基于与数据请求相关联的块映射身份存在于高速缓存中的确定，与数据请求相关联的块映射标识和根页面。 该实施例继续，通过从共享存储器复制存储的逻辑页面并且将逻辑页面的较低时间戳值设置为与存储的逻辑页面相关联的时间戳以及逻辑页面的较高时间戳值来由节点检索逻辑页面 基于逻辑页面不存在于高速缓存中的确定，该页面与数据请求相关联的时间戳。

公开(公告)号：US20060101081A1

公开(公告)日：2006-05-11

申请号：US10904263

申请日：2004-11-01

Applicant: Mei-Lin Lin ,  Fei Zhou ,  Joe Francis ,  Srikanth Sampath ,  Satya Ramachandran ,  Gangavara Prasad Varakur

Inventor： Mei-Lin Lin ,  Fei Zhou ,  Joe Francis ,  Srikanth Sampath ,  Satya Ramachandran ,  Gangavara Prasad Varakur

IPC: G06F17/30

CPC classification number: G06F17/30362 ,  Y10S707/99938

Abstract: A distributed database system providing data and space management methodology is described. In one embodiment, for example, a method is described for detection of deadlocks in a distributed database system comprising a plurality of servers sharing access to data, the method comprises steps of: in response to a task at a first server waiting to obtain a lock regulating access to data, sending a search request including lock information to a second server holding the lock; at the second server, examining dependencies of the task holding the lock based on the lock information received with the search request and local lock information; if the task holding the lock is waiting to obtain a lock held by an additional server, forwarding the search request and local lock information to the additional server; repeating the examining and forwarding steps until all dependencies are examined; and responding to the search request indicating whether a deadlock was detected and providing lock information found.

Abstract translation: 描述了提供数据和空间管理方法的分布式数据库系统。 在一个实施例中，例如，描述了一种用于在包括共享数据访问的多个服务器的分布式数据库系统中检测死锁的方法，所述方法包括以下步骤：响应于第一服务器处的等待获得锁定的任务 调节对数据的访问，向包含锁定的第二服务器发送包括锁定信息的搜索请求; 在第二服务器处，基于利用搜索请求和本地锁定信息接收到的锁定信息来检查保持锁定的任务的依赖性; 如果持有锁的任务正在等待获得由附加服务器持有的锁定，则将搜索请求和本地锁定信息转发到附加服务器; 重复检查和转发步骤，直到检查所有依赖关系; 并响应搜索请求，指示是否检测到死锁并提供找到的锁定信息。