公开(公告)号：US20060026154A1

公开(公告)日：2006-02-02

申请号：US10902583

申请日：2004-07-30

申请人： Mehmet Altinel ,  Christof Bornhoevd ,  Chandrasekaran Mohan ,  Mir Pirahesh ,  Berthold Reinwald ,  Saileshwar Krishnamurthy

发明人： Mehmet Altinel ,  Christof Bornhoevd ,  Chandrasekaran Mohan ,  Mir Pirahesh ,  Berthold Reinwald ,  Saileshwar Krishnamurthy

IPC分类号： G06F17/00

CPC分类号： G06F17/3048 ,  Y10S707/99933

摘要： A local database cache enabling persistent, adaptive caching of either full or partial content of a remote database is provided. Content of tables comprising a local cache database is defined on per-table basis. A table is either: defined declaratively and populated in advance of query execution, or is determined dynamically and asynchronously populated on-demand during query execution. Based on a user input query originally issued against a remote DBMS and referential cache constraints between tables in a local database cache, a Janus query plan, comprising local, remote, and probe query portions is determined. A probe query portion of a Janus query plan is executed to determine whether up-to-date results can be delivered by the execution of a local query portion against a local database cache, or whether it is necessary to retrieve results from a remote database by executing a remote query portion of Janus query plan.

摘要翻译： 提供本地数据库缓存，实现远程数据库的完整或部分内容的持久自适应缓存。 包含本地缓存数据库的表的内容基于每个表进行定义。 表是：在查询执行之前以声明方式和填充方式定义，或者在查询执行期间按需动态和异步地填充表。 基于最初针对远程DBMS发出的用户输入查询和本地数据库高速缓存中的表之间的参考高速缓存约束，确定包括本地，远程和探测查询部分的Janus查询计划。 执行Janus查询计划的探查查询部分以确定是否可以通过对本地数据库高速缓存执行本地查询部分来传递最新结果，或者是否需要通过以下方式从远程数据库检索结果： 执行Janus查询计划的远程查询部分。

公开(公告)号：US5761660A

公开(公告)日：1998-06-02

申请号：US691273

申请日：1996-08-01

申请人： Jeffrey William Josten ,  Tina Louise Masatani ,  Chandrasekaran Mohan ,  Inderpal S. Narang ,  James Zu-Chia Teng

发明人： Jeffrey William Josten ,  Tina Louise Masatani ,  Chandrasekaran Mohan ,  Inderpal S. Narang ,  James Zu-Chia Teng

IPC分类号： G06F12/00 ,  G06F11/14 ,  G06F17/30

CPC分类号： G06F17/30362 ,  G06F11/1471 ,  Y10S707/99938 ,  Y10S707/99952 ,  Y10S707/99953

摘要： A computer-implemented method for minimizing the amount of time to access current data in a database which may be stored wholly in a DASD-oriented external storage subsystem or partly in DASD and partly in a stored high-speed electronic store while maintaining coherency of the data with respect to multiple user systems.

摘要翻译： 一种计算机实现的方法，用于最小化访问数据库中当前数据的时间量，其可以完全存储在面向DASD的外部存储子系统中，或者部分地存储在DASD中，部分存储在存储的高速电子存储中，同时保持 相对于多个用户系统的数据。

公开(公告)号：US5493668A

公开(公告)日：1996-02-20

申请号：US860806

申请日：1992-03-30

申请人： David A. Elko ,  Jeffrey A. Frey ,  Chandrasekaran Mohan ,  Inderpal S. Narang ,  Jeffrey M. Nick ,  Jimmy P. Strickland ,  Michael D. Swanson

发明人： David A. Elko ,  Jeffrey A. Frey ,  Chandrasekaran Mohan ,  Inderpal S. Narang ,  Jeffrey M. Nick ,  Jimmy P. Strickland ,  Michael D. Swanson

IPC分类号： G06F12/08 ,  G06F12/12 ,  G06F12/02 ,  G06F13/00

CPC分类号： G06F12/084 ,  G06F12/0868 ,  G06F12/0804 ,  G06F12/128

摘要： A high-speed cache is shared by a plurality of independently-operating data systems in a multi-system data sharing complex. Each data system has access both to the high-speed cache and the lower-speed, secondary storage for obtaining and storing data. Management logic and the high-speed cache assures that a block of data obtained form the cache for entry into the secondary storage will be consistent with the version of the block of data in the shared cache with non-blocking serialization allowing access to a changed version in the cache while castout is being performed. Castout classes are provided to facilitate efficient movement from the shared cache to DASD.

摘要翻译： 高速缓存由多系统数据共享复合体中的多个独立操作的数据系统共享。 每个数据系统都可以访问高速缓存和低速二级存储，以获取和存储数据。 管理逻辑和高速缓存确保从高速缓存获得的数据块进入辅助存储将与共享高速缓存中的数据块版本一致，具有允许访问更改版本的非阻塞序列化 在执行castout时的缓存中。 提供了Castout类，以便有效地从共享缓存移动到DASD。

公开(公告)号：US5455944A

公开(公告)日：1995-10-03

申请号：US31774

申请日：1993-03-15

申请人： Donald J. Haderle ,  Chandrasekaran Mohan

发明人： Donald J. Haderle ,  Chandrasekaran Mohan

IPC分类号： G06F9/46 ,  G06F17/30 ,  G06F12/00 ,  G06F12/16

CPC分类号： G06F9/466 ,  Y10S707/99953

摘要： Database files containing records include pages called free space inventory pages (FSIPs) describing field space information relating to data pages. In a transaction processing system, the invention provides correct sequences for logging of updates to FSIPs when the updates are required by updates or UNDOs to data records. If, during operation to insert a data record to a data page, the FSIP containing free space information for the page indicates that the page is empty and there are no uncommitted deletes to the page, page I/O is avoided by formatting the page directly in a data buffer pool without reading the page from disk. During a cursor stability-level table scan with data record-level locking, excessive I/O and some record locking are avoided by using space reservation fields on an FSIP to ensure that there is no space reserved on the data page for a later undo of uncommitted data records deletes from the page.

摘要翻译： 包含记录的数据库文件包括描述与数据页相关的字段空间信息的称为可用空间清单页（FSIP）的页面。 在事务处理系统中，当更新或UNDO需要更新到数据记录时，本发明提供用于记录对FSIP的更新的正确序列。 如果在操作期间将数据记录插入数据页面，则包含该页面的可用空间信息的FSIP指示页面为空，并且没有未提交的页面删除，通过直接格式化页面来避免页面I / O 在没有从磁盘读取页面的数据缓冲池中。 在具有数据记录级别锁定的光标稳定级别表扫描期间，通过使用FSIP上的空间预留字段来避免过多的I / O和某些记录锁定，以确保在数据页面上没有保留的空间以便稍后撤消 未提交的数据记录从页面中删除。

公开(公告)号：US5287473A

公开(公告)日：1994-02-15

申请号：US627315

申请日：1990-12-14

申请人： Chandrasekaran Mohan ,  Inderpal S. Narang

发明人： Chandrasekaran Mohan ,  Inderpal S. Narang

IPC分类号： G06F12/08 ,  G06F12/12 ,  G06F13/14

CPC分类号： G06F12/128 ,  G06F12/084 ,  G06F12/0866

摘要： A high-speed cache is shared by a plurality of independently-operating data systems in a multi-system data sharing complex. Each data system has access both to the high-speed cache and the lower-speed, secondary storage for obtaining and storing data. Management logic and the high-speed cache assures that a block of data obtained form the cache for entry into the secondary storage will be consistent with the version of the block of data in the shared cache.

摘要翻译： 高速缓存由多系统数据共享复合体中的多个独立操作的数据系统共享。 每个数据系统都可以访问高速缓存和低速二级存储，以获取和存储数据。 管理逻辑和高速缓存确保从高速缓存获得的用于进入辅助存储器的数据块将与共享缓存中的数据块的版本一致。

公开(公告)号：US5247672A

公开(公告)日：1993-09-21

申请号：US480700

申请日：1990-02-15

申请人： Chandrasekaran Mohan

发明人： Chandrasekaran Mohan

IPC分类号： G06F9/46 ,  G06F9/52 ,  G06F12/00 ,  G06F15/00 ,  G06F17/30

CPC分类号： G06F9/466 ,  G06F9/526 ,  G06F2201/825 ,  G06F2201/87 ,  Y10S707/99938

摘要： Apparatus and method for reading data pages in a transaction processing system without locking the pages are disclosed. The system maintains a Global.sub.-- Committed.sub.-- LSN identifying the oldest uncommitted transaction accessing any of the data, and Object.sub.-- Committed.sub.-- LSNs identifying the oldest uncommitted transactions accessing particular files, tables and indexes. Each data page includes a Page.sub.-- LSN identifying the last transaction to have updated the page. To read a page, a transaction first latches the pages, and compares the page's Page.sub.-- LSN with the Global.sub.-- Committed.sub.-- LSN, or with the page's respective Object.sub.-- Committed.sub.-- LSN. If the Page.sub.-- LSN is older than the Committed.sub.-- LSN with which it was compared, then the transaction reads the page without locking it, since there can be no uncommitted transaction in process which might have updated the page's data. However if the Page.sub.-- LSN is younger than the Committed.sub.-- LSN, the page is locked before being read.

公开(公告)号：US5123104A

公开(公告)日：1992-06-16

申请号：US179190

申请日：1988-04-08

申请人： Frank E. Levine ,  Chandrasekaran Mohan

发明人： Frank E. Levine ,  Chandrasekaran Mohan

IPC分类号： G06F12/00 ,  G06F17/30

CPC分类号： G06F17/30327 ,  G06F17/30348 ,  Y10S707/99931

摘要： A method and apparatus for concurrent modifications of an index tree in a transaction processing system. The index tree includes at least one root node having a key record reference to one or more nodes in a next lower ordered level and at least one bottom node providing access to key records. Transactions including a structure modification operation are performed by traversing the index tree to the selected node and then setting an indication of the pendency of a structure modification operation. Concurrent key record inserts or deletes are permitted throughout the index tree where no indication of a pending structure modification operation is present and are delayed where a pending structure modification operation is indicated. Similarly, transactions which include a key record delete may require a structure modification operation in the event the transaction does not reach new point of consistency and must be undone. Therefore, an indication of each key record delete which has not yet reached a new point of consistency is set and concurrent key record inserts or deletes are also delayed until the possibility of a structure modification operation is completed.

公开(公告)号：US20130290283A1

公开(公告)日：2013-10-31

申请号：US13596990

申请日：2012-08-28

申请人： Ru Fang ,  Bin He ,  Hui-I Hsiao ,  Chandrasekaran Mohan

发明人： Ru Fang ,  Bin He ,  Hui-I Hsiao ,  Chandrasekaran Mohan

IPC分类号： G06F7/00

CPC分类号： G06F16/2379

摘要： Embodiments of a method are described. In one embodiment, the method is a method for executing and supporting transactions. The method includes receiving a transaction comprising a command and data. The method includes writing the data to a transaction manager on a persistent memory device. The transaction manager also maintains a status of the transaction and reference to entries within memory that are manipulated by the transaction. The method also includes creating an in-memory log of the transaction in a first hash directory. The method includes committing a copy of the first hash directory to a second hash directory maintained on a persistent memory device.

摘要翻译： 描述方法的实施例。 在一个实施例中，该方法是用于执行和支持事务的方法。 该方法包括接收包括命令和数据的事务。 该方法包括将数据写入持久存储器设备上的事务管理器。 事务管理器还维护事务的状态以及由事务处理的内存中的条目的引用。 该方法还包括在第一散列目录中创建事务的内存中日志。 该方法包括将第一散列目录的副本提交到在持久存储器设备上维护的第二散列目录。

公开(公告)号：US5557791A

公开(公告)日：1996-09-17

申请号：US325942

申请日：1994-10-19

申请人： Josephine M. Cheng ,  Chandrasekaran Mohan ,  Mir H. Pirahesh

发明人： Josephine M. Cheng ,  Chandrasekaran Mohan ,  Mir H. Pirahesh

IPC分类号： G06F17/30

CPC分类号： G06F17/30498 ,  Y10S707/99932

摘要： A computer database system utilizes a method for performing a right outer join of database tables without sorting the inner table (T.sub.2). The processing of each tuple in the outer table (T.sub.1) includes the preservation in the joint output of all tuples in T.sub.2 which are in its responsibility region. The initialization step of the process preserves in the join output all of the tuples in T.sub.2 which have column set values less than the lowest column set value in T.sub.1, i.e. the first tuple in T.sub.1, since T.sub.1 is sorted or accessed using a sorted index. The responsibility region for tuples in T.sub.1, other than the last tuple, is defined as those tuples which have column set values less than the column set value for the next tuple in T.sub.1 and greater than or equal to the column set value for the current T.sub.1 tuple. The last tuple in T.sub.1 must preserve all of the tuples in T.sub.2 which have not already been preserved in T.sub.2, i.e. all tuples greater than or equal to its column set value. If T.sub.1 has duplicate values for the column set value, only the last one preserves the associated T.sub.2 tuples. Additional methods for parallel execution of the outer join methods and methods for applying the outer join methods to subqueries (i.e., an All (or universal) Right Join (ARJOIN) and an Existential Right Join (ERJOIN)) are described.

摘要翻译： 计算机数据库系统利用用于执行数据库表的右外连接的方法，而不排序内表（T2）。 外表（T1）中每个元组的处理包括在其责任区域的T2中所有元组的联合输出中的保存。 该进程的初始化步骤在连接输出中保留所有T2中的元组，它们的列设置值小于T1中的最低列设置值，即T1中的第一个元组，因为使用排序索引对T1进行排序或访问。 T1中的元组的责任区域除了最后一个元组之外，被定义为具有小于T1中下一个元组的列设置值的列设置值大于或等于当前T1的列设置值的元组 元组 T1中的最后一个元组必须保留T2中尚未保存在T2中的所有元组，即大于或等于其列设置值的所有元组。 如果T1具有列设置值的重复值，则只有最后一个值保留关联的T2元组。 描述了用于并行执行外连接方法和将外连接方法应用于子查询（即，全（或通用）右连接（ARJOIN）和存在右连接（ERJOIN））的附加方法。

公开(公告)号：US5333303A

公开(公告)日：1994-07-26

申请号：US678526

申请日：1991-03-28

申请人： Chandrasekaran Mohan

发明人： Chandrasekaran Mohan

IPC分类号： G06F12/00 ,  G06F11/14

CPC分类号： G06F11/1471 ,  G06F2201/80 ,  G06F2201/87

摘要： Enhanced data availability occurs in a write-ahead logging, transaction-oriented database system by permitting new transactions to acquire access to data while restart recovery operations are proceeding. The invention permits new transactions to acquire access to data during restart recovery UNDO processing on the condition that the last update to the data occurred before a commit point measured by the beginning of the earliest-commencing transaction with uncommitted updates which was still executing when a system failure initiated restart recovery operations. During REDO processing, a transaction is permitted access to data which, in addition to meeting the commit point condition, is not in a data structure subject to the REDO processing.

摘要翻译： 增强的数据可用性发生在预写日志记录，面向事务的数据库系统中，允许新事务获取对数据的访问，同时重新启动恢复操作正在进行。 本发明允许新事务在重新启动恢复UNDO处理期间获取对数据的访问，条件是数据的最后更新在由最早开始事务的开始测量的提交点之前发生，其中未提交的更新在系统中仍在执行时 故障启动重启恢复操作。 在REDO处理期间，允许访问数据，除了满足提交点条件之外，数据不在经受REDO处理的数据结构中。