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1.发明授权Complied objective referential constraints in a relational database having dual chain relationship descriptors linked in data record tables 失效具有链接在数据记录表中的双链关系描述符的关系数据库中的合并目标参考约束
公开(公告)号：US5133068A
公开(公告)日：1992-07-21
申请号：US754227
申请日：1991-08-28
CPC分类号： G06F17/30371
摘要： An implementation of referential integrity in which descriptions of referential constraints are compiled into meta-data descriptions of the constraint rules and specifications. The meta-data descriptions of the constraints are stored in the form of objects called relationship descriptors. Each relationship descriptor contains a complete description of a referential constraint, either directly or by means of pointers to other objects such as record and index descriptors which contain information comprised in the constraint's specification. The relationship descriptors are linked into two types of chains by symbolic pointers. One type of relationship descriptor chain connects all relationship descriptors which have a common parent table. The other type of relationship descriptor chain connects relationship descriptors with common dependent tables. Both types of chains are anchored in respective fields in the tables' record descriptors. The use of meta-data descriptors facilitates both ready modification of the constraints, and speedy enforcement of the constraints by a single, shared procedure which may be embedded in the data base manager.
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2.发明授权
公开(公告)号：US4961134A
公开(公告)日：1990-10-02
申请号：US219514
申请日：1988-07-15
CPC分类号： G06F17/30339 , G06F12/0238 , Y10S707/99938 , Y10S707/99953
摘要： A page-accessing method in a segmented tablespace 10 which eliminates unnecessary reading and locking. The tablespace comprises data pages 18 grouped into identically-sized segments 16, each segment storing data for a single table. A status indicator 26 for each data page of a segment is kept in a separate segment control block 20 stored on a space map page 14. Five data page status indicator values are maintained: (1) FULL (26a) - entirely full of current data; (2) PARTIALLY FULL (26b) - partially full of current data; (3) UNFORMATTED (26c) - empty; contains no data; (4) MASS DELETE (26d) - contains only obsolete data because of an unqualified deletion (mass delete) of data; or (5) QUALIFIED DELETE (26e) - contains only obsolete data because of a qualified deletion of data.When scanning over the data in a segment, UNFORMATTED and MASS DELETE pages are skipped. QUALIFIED DELETE pages are locked, and then skipped if they still contain only obsolete data when the lock is obtained. When inserting data into pages, preliminary reads of UNFORMATTED and MASS DELETE pages are avoided. Data integrity is ensured by placing integrity checking bits at the beginning and end of each page. If the bits contain the same value, the page's data integrity is intact. If the bits are different, the page's previous consistent contents are recovered from the log records.
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3.发明授权Method for managing lock escalation in a multiprocessing, multiprogramming environment 失效用于在多处理，多重编程环境中管理锁升级的方法
公开(公告)号：US4716528A
公开(公告)日：1987-12-29
申请号：US825508
申请日：1986-02-03
CPC分类号： G06F9/52
摘要： A method utilizing a coordinated pair of locking limits for managing concurrency and lock granularity tradeoff relations. A first limit is placed on the number of small granularity locks per resource. A second limit is placed on the number of locks assignable to each process. When the first number of small locks is reached, the method withdraws the small locks and grants only one lock to the entire resource (lock escalation). When a process requests an additional lock over the second limit, the lock is refused.
摘要翻译： 一种利用协调的一对锁定限制来管理并发和锁定粒度权衡关系的方法。 第一个限制是每个资源的小粒度锁的数量。 第二个限制是可分配给每个进程的锁的数量。 当达到第一个小锁的数量时，该方法撤销小锁，并向整个资源授予一个锁（锁升级）。 当一个进程请求超过第二个限制的额外锁定时，该锁将被拒绝。
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4.发明授权Method for assuring atomicity of multi-row update operations in a database system 失效确保数据库系统中多行更新操作的原子性的方法
公开(公告)号：US4498145A
公开(公告)日：1985-02-05
申请号：US393967
申请日：1982-06-30
CPC分类号： G06F17/30595 , G06F11/1474 , G06F9/463 , G06F2201/80 , Y10S707/99953
摘要： A method for assuring atomicity of user requested multi-row update operations to tables such as in a relational database, guarantees that for any update operation that succeeds all stated effects will have occurred and that for any update operation that fails the system state as perceived by the user remains unchanged. This is accomplished by establishing, in response to a multi-row update operation request, an execution module of a program containing sets of machine language code instructions implementing the update operation request with a savepoint request at the beginning of the execution module of the program. For each set of machine language code instructions in or called by the execution module which modified the user perceived system state, information is logged to a soft log. Upon completing the execution module of the program, the savepoint is dropped, causing all soft log information recorded since the savepoint to be deleted and releasing all resources held to guarantee restoration of the user perceived system state at the time of the savepoint request. Responsive to the detection of an error during execution of the execution module of the program, the soft logged information is used to restore the user perceived state to that existing at the time of the savepoint request.
摘要翻译： 确保用户请求的多行更新操作对诸如关系数据库之类的表的原子性的方法保证对于所有已经发生的所有效果的任何更新操作都会发生，并且对于任何由于 用户保持不变。 这是通过响应于多行更新操作请求，在程序的执行模块的开始处建立包含实现具有保存点请求的更新操作请求的机器语言代码指令的程序的程序的执行模块来实现的。 对于修改用户感知系统状态的执行模块中的每个机器语言代码指令集或调用，信息被记录到软日志。 完成程序的执行模块后，保存点被删除，导致从保存点记录的所有软日志信息被删除，并释放保存的所有资源，以保证在保存点请求时恢复用户感知的系统状态。 响应于在执行程序的执行模块期间检测到错误，软记录信息用于将用户感知状态恢复到保存点请求时存在的状态。
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5.发明授权Method and system for efficiently providing maintenance activity on a relational database that is utilized within a processing system 有权用于在处理系统内使用的关系数据库上有效提供维护活动的方法和系统公开(公告)号：US06542904B2
公开(公告)日：2003-04-01
申请号：US09364645
申请日：1999-07-30
IPC分类号： G06F1730
CPC分类号： G06F17/30595 , Y10S707/99952 , Y10S707/99953
摘要： A method and system for efficiently providing maintenance activity on a relational database that is utilized within a processing system is disclosed. The relational database includes a pool of threads and a plurality of resources. The pool of threads receive requests from a plurality of clients and control the plurality of resources. The method and system comprise determining that a maintenance activity is required and providing a first command that initiates a first process which terminates all threads in the pool of threads if the maintenance activity is required. The method and system further include providing a second command which initiates a second process after the maintenance activity has completed which causes the threads to be created and initiates the processing of requests. A system and method in accordance with the present invention based upon the determination that a maintenance activity is required causes the pool threads within a relational database to terminate and thus free up resources but also allows the connections from the clients to persist. Once the relational database resources are freed, the maintenance activity is performed, and thereafter distributed relational database processing is resumed.
摘要翻译： 公开了一种用于在处理系统内利用的关系数据库上有效提供维护活动的方法和系统。 关系数据库包括一个线程池和多个资源。 线程池接收来自多个客户端的请求并控制多个资源。 所述方法和系统包括确定需要维护活动并且提供启动第一进程的第一命令，如果需要维护活动，则终止所述线程池中的所有线程。 所述方法和系统还包括提供在维护活动完成之后启动第二进程的第二命令，其导致创建线程并启动请求的处理。 基于确定需要维护活动的本发明的系统和方法使得关系数据库内的池线程终止并因此释放资源，而且允许来自客户端的连接持久化。 一旦关系数据库资源被释放，则执行维护活动，然后恢复分布式关系数据库处理。
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6.发明授权
公开(公告)号：US4947320A
公开(公告)日：1990-08-07
申请号：US219513
申请日：1988-07-15
CPC分类号： G06F17/3051 , G06F17/30371 , Y10S707/99952
摘要： A method is disclosed for enforcing referential constraints on a record-by-record basis, immediately before or after each record is manipulated and while the record is still accessed, significantly improving the system's performance. Each record is visited only once to do both the constraint checking and the manipulation (insert/update/delete). If the constraint checking fails, then the entire relational operation of which the record manipulation is a part is backed out. For insertions, each record is first inserted 30, and then constraints respective the record are enforced 32,34. For updates, the record is updated 48 after constraints respecting the record's primary key are enforced 40,42, and before constraints respecting its foreign key(s) are enforced 44,46. Deletions are performed 52 before the constraints on the deleted record are enforced 54,56. Cascade deleted 58 are handled recursively 60. The method correctly processes cyclic constraints and self-referencing rows without special handling.
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