公开(公告)号：US20080065670A1

公开(公告)日：2008-03-13

申请号：US11934986

申请日：2007-11-05

申请人： Sang Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

发明人： Sang Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

IPC分类号： G06F17/30

CPC分类号： G06F17/30356 ,  G06F17/30351 ,  Y10S707/99933

摘要： An optimistic, latch-free index traversal (“OLFIT”) concurrency control scheme is disclosed for an index structure for managing a database system. In each node of an index tree, the OLFIT scheme maintains a latch, a version number, and a link to the next node at the same level of the index tree. Index traversal involves consistent node read operations starting from the root. To ensure the consistency of node read operations without latching, every node update operation first obtains a latch and increments the version number after update of the node contents. Every node read operation begins with reading the version number into a register and ends with verifying if the current version number is consistent with the register-stored version number. If they are the same, the read operation is consistent. Otherwise, the node read is retried until the verification succeeds. The concurrency control scheme of the present invention is applicable to many index structures such as the B+-tree and the CSB+-tree.

摘要翻译： 公开了一种用于管理数据库系统的索引结构的乐观，无锁定索引遍历（“OLFIT”）并发控制方案。 在索引树的每个节点中，OLFIT方案维护锁存器，版本号和到索引树的同一级别的下一个节点的链接。 索引遍历涉及从根开始的一致的节点读取操作。 为了确保节点读取操作的一致性，无需锁存，每个节点更新操作首先获取锁存器，并在更新节点内容后增加版本号。 每个节点读取操作都从读取寄存器中的版本号开始，并结束验证当前版本号是否与寄存器存储的版本号一致。 如果它们相同，则读取操作是一致的。 否则，重新尝试节点读取，直到验证成功。 本发明的并发控制方案适用于诸如B +树和CSB +树的许多索引结构。

公开(公告)号：US07293028B2

公开(公告)日：2007-11-06

申请号：US10162731

申请日：2002-06-04

申请人： Sang K. Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

发明人： Sang K. Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

IPC分类号： G06F7/00 ,  G06F17/30

CPC分类号： G06F17/30356 ,  G06F17/30351 ,  Y10S707/99933

摘要： An optimistic, latch-free index traversal (“OLFIT”) concurrency control scheme is disclosed for an index structure for managing a database system. In each node of an index tree, the OLFIT scheme maintains a latch, a version number, and a link to the next node at the same level of the index tree. Index traversal involves consistent node read operations starting from the root. To ensure the consistency of node read operations without latching, every node update operation first obtains a latch and increments the version number after update of the node contents. Every node read operation begins with reading the version number into a register and ends with verifying if the current version number is consistent with the register-stored version number. If they are the same, the read operation is consistent. Otherwise, the node read is retried until the verification succeeds. The concurrency control scheme of the present invention is applicable to many index structures such as the B+-tree and the CSB+-tree.

摘要翻译： 公开了一种用于管理数据库系统的索引结构的乐观，无锁定索引遍历（“OLFIT”）并发控制方案。 在索引树的每个节点中，OLFIT方案维护锁存器，版本号和到索引树的同一级别的下一个节点的链接。 索引遍历涉及从根开始的一致的节点读取操作。 为了确保节点读取操作的一致性，无需锁存，每个节点更新操作首先获取锁存器，并在更新节点内容后增加版本号。 每个节点读取操作都从读取寄存器中的版本号开始，并结束验证当前版本号是否与寄存器存储的版本号一致。 如果它们相同，则读取操作是一致的。 否则，重新尝试节点读取，直到验证成功。 本发明的并发控制方案适用于诸如B +树和CSB +树的许多索引结构。

公开(公告)号：US09454560B2

公开(公告)日：2016-09-27

申请号：US11934986

申请日：2007-11-05

申请人： Sang K. Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

发明人： Sang K. Cha ,  Sangyong Hwang ,  Kihong Kim ,  Keunjoo Kwon

IPC分类号： G06F17/30

CPC分类号： G06F17/30356 ,  G06F17/30351 ,  Y10S707/99933

摘要： An optimistic, latch-free index traversal (“OLFIT”) concurrency control scheme is disclosed for an index structure for managing a database system. In each node of an index tree, the OLFIT scheme maintains a latch, a version number, and a link to the next node at the same level of the index tree. Index traversal involves consistent node read operations starting from the root. To ensure the consistency of node read operations without latching, every node update operation first obtains a latch and increments the version number after update of the node contents. Every node read operation begins with reading the version number into a register and ends with verifying if the current version number is consistent with the register-stored version number. If they are the same, the read operation is consistent. Otherwise, the node read is retried until the verification succeeds. The concurrency control scheme of the present invention is applicable to many index structures such as the B+-tree and the CSB+-tree.

摘要翻译： 公开了一种用于管理数据库系统的索引结构的乐观，无锁定索引遍历（“OLFIT”）并发控制方案。 在索引树的每个节点中，OLFIT方案维护锁存器，版本号和到索引树的同一级别的下一个节点的链接。 索引遍历涉及从根开始的一致的节点读取操作。 为了确保节点读取操作的一致性，无需锁存，每个节点更新操作首先获取锁存器，并在更新节点内容后增加版本号。 每个节点读取操作都从读取寄存器中的版本号开始，并结束验证当前版本号是否与寄存器存储的版本号一致。 如果它们相同，则读取操作是一致的。 否则，重新尝试节点读取，直到验证成功。 本发明的并发控制方案适用于诸如B +树和CSB +树的许多索引结构。