公开(公告)号：US5864849A

公开(公告)日：1999-01-26

申请号：US767048

申请日：1996-12-16

申请人： Philip Lewis Bohannon ,  Rajeev Rastogi ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Philip Lewis Bohannon ,  Rajeev Rastogi ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F11/14 ,  G06F17/30

CPC分类号： G06F11/1469 ,  G06F11/1471 ,  Y10S707/99937 ,  Y10S707/99938 ,  Y10S707/99952 ,  Y10S707/99953

摘要： For use with an active database stored in volatile memory for direct revision thereof, the active database having multiple checkpoints and a stable log, having a tail stored in the volatile memory, for tracking revisions to the active database to allow corresponding revisions to be made to the multiple checkpoints, the active database subject to corruption, a system for, and method of, restoring the active database and a computer system containing the same. The system includes: (1) a checkpoint determination controller that determines which of the multiple checkpoints is a most recently completed checkpoint and copies the most recently completed checkpoint to the volatile memory to serve as an unrevised database for reconstructing the active database and (2) a revision application controller that retrieves selected ones of the revisions from the stable log and the tail and applies the revisions to the unrevised database thereby to restore the active database. In an advantageous embodiment, the applied revisions include log records at an operation level (lower level of abstration than transactions), and the revision application controller, using memory locks while restoring the active database, releases ones of the memory locks as a function of applying ones of the log records.

摘要翻译： 为了与存储在易失性存储器中的活动数据库一起用于其直接修订，活动数据库具有多个检查点和稳定的日志，其具有存储在易失性存储器中的尾部，用于跟踪活动数据库的修订以允许相应的修订 多个检查点，活动数据库受到破坏，恢复活动数据库的系统和方法以及包含该活动数据库的计算机系统。 该系统包括：（1）检查点确定控制器，其确定多个检查点中的哪一个是最近完成的检查点，并将最近完成的检查点复制到易失性存储器，以用作用于重建活动数据库的未修改的数据库;以及（2） 修订应用程序控制器，从稳定日志和尾部检索选定的修订版本，并将修订版本应用到未修改的数据库，从而恢复活动数据库。 在有利的实施例中，所应用的修订包括在操作级别（比交易更低级别）的日志记录，以及在恢复活动数据库时使用存储器锁定的修订应用程序控制器，释放作为应用的函数的存储器锁 一些日志记录。

公开(公告)号：US6125371A

公开(公告)日：2000-09-26

申请号：US914744

申请日：1997-08-19

申请人： Philip L. Bohannon ,  Dennis W. Leinbaugh ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Philip L. Bohannon ,  Dennis W. Leinbaugh ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F17/30

CPC分类号： G06F17/30309 ,  G06F2216/09 ,  Y10S707/99954

摘要： For use with a database of data records stored in a memory, a system and method for increasing a memory capacity and a memory database employing the system or the method. The system includes: (1) a time stamping controller that assigns a time stamp to transactions to be performed on the database, the time stamp operates to preserve an order of the transactions, (2) a versioning controller that creates multiple versions of ones of the data records affected by the transactions that are update transactions and (3) an aging controller, which is associated with each of the time stamping and versioning controllers, that monitors a measurable characteristic of the memory and deletes ones of the multiple versions of the ones of the data records in response to the time stamp and the measurable characteristic thereby to increase memory capacity.

摘要翻译： 用于存储在存储器中的数据记录的数据库，用于增加存储器容量的系统和方法以及采用该系统或方法的存储器数据库。 该系统包括：（1）时间戳控制器，为在数据库上执行的事务分配时间戳，时间戳操作以保持事务的顺序，（2）版本控制器，其创建多个版本的 由更新事务的事务影响的数据记录和（3）与每个时间戳和版本控制器相关联的老化控制器，其监视存储器的可测量特性并删除其中的一个版本 的数据记录，以响应于时间戳和可测量的特性，从而增加存储器容量。

公开(公告)号：US06374264B1

公开(公告)日：2002-04-16

申请号：US09207926

申请日：1998-12-09

申请人： Philip L. Bohannon ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Philip L. Bohannon ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F1730

CPC分类号： G06F11/1474 ,  G06F11/1471 ,  G06F2201/80 ,  Y10S707/99932 ,  Y10S707/99953

摘要： A method of detecting and recovering from data corruption of a database is characterized by the step of protecting data of the database with codewords, one codeword for each region of the database; and verifying that a codeword matches associated data before the data is read from the database to prevent transaction-carried corruption. A deferred maintenance scheme is recommended for the codewords protecting the database such that the method of detecting and recovering from data corruption of a database may comprise the steps of protecting data of the database with codewords, one codeword for each region of the database; and asynchronously maintaining the codewords to improve concurrency of the database. Moreover, the database may be audited by using the codewords and noting them in a table and protecting regions of the database with latches. Once codeword values are computed and checked against noted values in memory, a flush can cause codewords from outstanding log records to be applied to the stored codeword table.

摘要翻译： 一种从数据库的数据损坏中检测和恢复的方法的特征在于利用码字保护数据库的数据的步骤，数据库的每个区域的一个码字; 并且在从数据库读取数据之前验证码字匹配相关联的数据以防止交易携带的损坏。 对于保护数据库的代码字，建议使用延迟维护方案，以便检测和恢复数据库的数据损坏的方法可以包括以下代码字来保护数据库的数据的步骤，数据库的每个区域的一个代码字; 并且异步地维护码字以改善数据库的并发性。 此外，可以通过使用码字来审核数据库，并在表中注明数据库，并用锁存器保护数据库的区域。 一旦根据存储器中的标记值计算和检查码字值，则刷新可以使来自未完成的日志记录的码字被应用于存储的码字表。

公开(公告)号：US6122645A

公开(公告)日：2000-09-19

申请号：US2635

申请日：1998-01-05

申请人： Philip L. Bohannon ,  Dennis W. Leinbaugh ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Philip L. Bohannon ,  Dennis W. Leinbaugh ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F17/30

CPC分类号： G06F17/30309 ,  Y10S707/99953 ,  Y10S707/99954

摘要： For use with a database of data records organized into components, the database stored in a memory, a processing system for, and method of, physically versioning the database. In one embodiment, the processing system includes: (1) a component copier that creates a physical copy of an original component to be affected by an update transaction to be applied to the database, and that causes pointers in nodes of the physical copy to point to other nodes in the physical copy, (2) a data updater, associated with the component copier, that applies the update transaction to the physical copy to create therefrom a new physical version, the original component remaining unaffected by the update transaction and (3) a pointer updater, associated with the data updated, that employs an atomic word write to revise a component pointer, associated with the database, to cause the pointer to point to the new physical version.

摘要翻译： 为了与组织成组件的数据记录的数据库一起使用，存储在内存中的数据库，处理系统以及对数据库进行物理版本化的方法。 在一个实施例中，处理系统包括：（1）组件复印机，其创建将要被应用于数据库的更新事务影响的原始组件的物理副本，并且使物理副本的节点中的指针指向 到物理副本中的其他节点，（2）与组件复印机相关联的数据更新器，将更新事务应用于物理副本以从其创建新的物理版本，原始组件不受更新事务的影响，（3 ）与更新的数据相关联的指针更新器，其使用原子字写入来修改与数据库相关联的组件指针，以使指针指向新的物理版本。

公开(公告)号：US06449623B1

公开(公告)日：2002-09-10

申请号：US09207927

申请日：1998-12-09

申请人： Philip L. Bohannon ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Philip L. Bohannon ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F1200

CPC分类号： G06F11/1474 ,  G06F11/1471 ,  G06F2201/80 ,  Y10S707/99932 ,  Y10S707/99953

摘要： A method of detecting and recovering from data corruption of a database is characterized by the step of logging information about reads of a database in memory to detect errors in data of the database, wherein said errors in data of said database arise from one of bad writes of data to the database, of erroneous input of data to the database by users and of logical errors in code of a transaction. The read logging method may be implemented in a plurality of database recovery models including a cache-recovery model, a prior state model a redo-transaction model and a delete transaction model. In the delete transaction model, it is assumed that logical information is not available to allow a redo of transactions after a possible error and the effects of transactions that read corrupted data are deleted from history and any data written by a transaction reading Ararat data is treated as corrupted.

摘要翻译： 从数据库的数据损坏中检测和恢复的方法的特征在于记录关于数据库在存储器中的读取的信息的步骤，以检测数据库的数据中的错误，其中所述数据库的数据中的错误来自坏写入之一 的数据，数据由用户错误地输入到数据库以及事务代码中的逻辑错误。 读取记录方法可以在包括高速缓存恢复模型，先前状态模型，重做事务模型和删除事务模型的多个数据库恢复模型中实现。 在删除事务模型中，假设逻辑信息不可用于允许在可能的错误之后重做事务，并且从历史中删除读取损坏的数据的事务的影响，并且处理由读取Ararat数据的事务写入的任何数据被处理 被破坏。

公开(公告)号：US06363403B1

公开(公告)日：2002-03-26

申请号：US09345826

申请日：1999-06-30

申请人： Prasan Roy ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

发明人： Prasan Roy ,  Srinivasan Seshadri ,  Abraham Silberschatz ,  Sundararajarao Sudarshan

IPC分类号： G06F1730

CPC分类号： G06F12/0261 ,  G06F17/30362 ,  G06F17/30368 ,  Y10S707/99944 ,  Y10S707/99957

摘要： A reference counting a garbage collection process employs a reference counting technique in which only the “last” detected strong pointer is followed to an object. Moreover, no assumptions are made about the phase locking used in the transaction and strict WAL is not followed. Indeed, a relatively restricted local traversal of the object graph is employed which leads to higher efficiency. Furthermore, in a client-server arrangement, updates made by a transaction running at the client may be reflected at the server after the transaction ends, and the updates are not required to be forced to the server before the end of the transaction.

摘要翻译： 对垃圾收集过程进行计数的参考采用一种引用计数技术，其中只有“最后”检测到的强指针被跟随到对象。 此外，没有对事务中使用的锁相进行假设，并且不遵循严格的WAL。 实际上，采用对象图的相对受限的局部遍历，这导致更高的效率。 此外，在客户端 - 服务器安排中，在事务结束之后，在客户机上运行的事务进行的更新可以在服务器处反映，并且在事务结束之前不需要将更新强制到服务器。

公开(公告)号：US06343296B1

公开(公告)日：2002-01-29

申请号：US09389337

申请日：1999-09-03

申请人： Mohana Krishna Lakhamraju ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Sundararajarao Sudarshan

发明人： Mohana Krishna Lakhamraju ,  Rajeev Rastogi ,  Srinivasan Seshadri ,  Sundararajarao Sudarshan

IPC分类号： G06F1730

CPC分类号： G06F17/30607 ,  Y10S707/99938 ,  Y10S707/99943 ,  Y10S707/99944

摘要： An on-line reorganization method of an object-oriented database with physical references involves a novel fuzzy traversal of the database, or a partition thereof, to identify the approximate parents of all migrating objects. Where the entire database is traversed the process begins from its persistent root. For traversals of a partition the process begins from each object with a reference pointing to it from outside the partition. To facilitate the identification of these inter-partitional objects an External Reference Table (“ERT”) is maintained. During the fuzzy traversal all new inserted and deleted references are tracked in a Temporary Reference Table (“TRT”). After the fuzzy traversal is completed, for each migrating object, a lock is obtained on the identified approximate parents and on all new parents in which references to the object were inserted, as indicated by the TRT. Based on the information in the TRT, locks are released on all approximate parents whose references to the object have been deleted. The references to the migrating object in the remaining set of locked parents are updated, the object is relocated and the locks are released. Alternatively, each parent of a migrating object can be individually locked, updated and released.

摘要翻译： 具有物理引用的面向对象数据库的在线重组方法涉及数据库或其分区的新颖的模糊遍历，以识别所有迁移对象的近似父母。 在整个数据库遍历的过程中，进程从其持久根开始。 对于遍历分区，进程从每个对象开始，引用从分区外部引用它。 为了便于识别这些跨部门对象，维护了外部参考表（“ERT”）。 在模糊遍历期间，所有新插入和删除的引用将在临时参考表（“TRT”）中进行跟踪。 模糊遍历完成后，对于每个迁移对象，在所标识的近似父母以及所有新父母上获取锁定，其中插入了对象的引用，如TRT所示。 根据TRT中的信息，在对对象的引用已被删除的所有近似父类上释放锁。 在剩余的一组锁定的父项中对迁移对象的引用被更新，对象被重新定位并且锁被释放。 或者，可以单独锁定，更新和释放迁移对象的每个父项。

公开(公告)号：US6012062A

公开(公告)日：2000-01-04

申请号：US607983

申请日：1996-03-04

申请人： Hosagrahar Visvesvaraya Jagadish ,  Ramarao Kanneganti ,  Sundararajarao Sudarshan

发明人： Hosagrahar Visvesvaraya Jagadish ,  Ramarao Kanneganti ,  Sundararajarao Sudarshan

IPC分类号： G06F12/00 ,  G06T9/00 ,  G11B20/00 ,  G11B20/10 ,  H03M7/30 ,  H03M7/40 ,  G06F17/30

CPC分类号： H03M7/3086 ,  G06T9/005 ,  G11B20/00007 ,  G11B20/10 ,  G11B2020/10916 ,  Y10S707/99942

摘要： A data base system buffers incoming records according to destination in the disk or non-volatile memory. The data is compressed and transferred to disk when sufficient data has been accumulated for a particular disk destination. Techniques for compressing the compression dictionary as well as the data stream are described.

摘要翻译： 数据库系统根据磁盘或非易失性存储器中的目的地缓存传入记录。 当为特定的磁盘目的地累积了足够的数据时，数据被压缩并传输到磁盘。 描述了用于压缩压缩字典以及数据流的技术。

公开(公告)号：US20080071785A1

公开(公告)日：2008-03-20

申请号：US11468928

申请日：2006-08-31

申请人： Govind Kabra ,  Ravishankar Ramamurthy ,  Sundararajarao Sudarshan

发明人： Govind Kabra ,  Ravishankar Ramamurthy ,  Sundararajarao Sudarshan

IPC分类号： G06F17/30

CPC分类号： G06F17/30471 ,  G06F17/30306 ,  G06F21/6227

摘要： Fine-grained access control for querying a database with low overhead and safety plans. In a view placement approach, base relations of the query expression are replaced by views that are appropriate for the particular user. Information leakage via UDF pushing, exception processing, and error messages can be prevented by generating safe plans. An existing query optimizer can be modified to perform redundancy removal and safe plan implementation. Subsumption testing available in materialized view matching can be exploited by the query optimizer. Authorization inference is exploited to generate safe plans.

摘要翻译： 用于以低开销和安全计划查询数据库的细粒度访问控制。 在视图放置方法中，查询表达式的基础关系被替换为适合特定用户的视图。 可以通过生成安全计划来防止通过UDF推送，异常处理和错误消息的信息泄漏。 可以修改现有的查询优化器，以执行冗余删除和安全计划实施。 查询优化器可以利用实体​​化视图匹配中的可用度量测试。 利用授权推理来制定安全计划。

公开(公告)号：US5623670A

公开(公告)日：1997-04-22

申请号：US390179

申请日：1995-02-17

申请人： Philip L. Bohannon ,  Jacques Gava ,  Daniel F. Lieuwen ,  Sundararajarao Sudarshan

发明人： Philip L. Bohannon ,  Jacques Gava ,  Daniel F. Lieuwen ,  Sundararajarao Sudarshan

IPC分类号： G06F15/16 ,  G06F9/46 ,  G06F9/52 ,  G06F15/177 ,  G06F13/14

CPC分类号： G06F9/52

摘要： A fast crash safe method and apparatus for enforcing mutually exclusive access to shared resources in a computer system through the use of semaphores. The acquisition and release of the semaphores is implemented at the user process level. An overestimate and underestimate of semaphore ownership are maintained in memory by library provided semaphore acquisition and release code. A cleanup routine reconciles the overestimate and underestimate to determine the ownership status of the semaphores.

摘要翻译： 一种快速崩溃的安全方法和装置，用于通过使用信号量来强制互操作地访问计算机系统中的共享资源。 信号量的获取和释放在用户进程级别实现。 通过图书馆提供的信号量采集和发布代码，对信号量所有权的过高估计和低估维持在记忆体中。 清理程序调和高估和低估以确定信号量的所有权状态。