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    • 1. 发明授权
    • Concurrency-control method and apparatus in a database management system
utilizing key-valued locking
    • 利用键值锁定的数据库管理系统中的并发控制方法和装置
    • US5485607A
    • 1996-01-16
    • US14188
    • 1993-02-05
    • David B. LometRussell J. Green
    • David B. LometRussell J. Green
    • G06F17/30
    • G06F17/30362Y10S707/99938
    • The concurrency-control mechanisms in a database-management system achieves high concurrency by using a lock-mode set larger than that conventionally employed for multi-granularity locking. In a system of key-valued locking in which locks on key-value ranges are acquired separately from the locks on the key values with which they are associated, the IX lock mode conventionally acquired on a range by update, insert, and delete operations is replaced with three separate lock modes respectively associated with those operations and invoked by them for range locking. In key-valued-locking systems in which ranges are locked commonly with the key-values associated with them, the mode set is further expanded so that each mode represents a different combination of range and key-value locks.
    • 数据库管理系统中的并发控制机制通过使用大于常规用于多粒度锁定的锁模式来实现高并发性。 在键值锁定系统中,键值范围的锁与其关联的键值分开获取锁定,通常通过更新,插入和删除操作在范围上获取的IX锁定模式是 替换为分别与这些操作相关联的三个单独的锁定模式,并由它们用于范围锁定。 在键值锁定系统中,范围与其相关联的键值通常被锁定,模式集进一步扩展,使得每个模式表示范围和键值锁定的不同组合。
    • 2. 发明授权
    • Key-range locking with index trees
    • 带索引树的关键范围锁定
    • US5440732A
    • 1995-08-08
    • US014181
    • 1993-02-05
    • David B. LometRussell J. Green
    • David B. LometRussell J. Green
    • G06F17/30
    • G06F17/30327G06F17/30362G06F17/30949Y10S707/99931Y10S707/99938
    • A database-management system (10) generates bounded-disorder indexes on its database keys. In such an index, the leaf nodes (51, 62) are large and are divided into a number of buckets (52, 54, 56, 58), only one of which ordinarily is accessed in any given single-record database operation. The key values in a leaf node are distributed among the leaf node's buckets in accordance with a hashing function. The lockable ranges locked for scanning functions are defined in accordance with key-valued locking, in which each lockable range is bounded by successive key values that exist in the database. But the multiple-bucket accesses that would otherwise be required, because of the hash-function distribution of key values among a node's several buckets, are avoided because the lockable ranges are defined by the sequence of key values in the bucket rather than in the node. In addition to the existing key values, moreover, the buckets' key-value limits are also employed to bound lockable ranges, even if no database records contain those key-value limits. This prevents end-of-bucket insertions and deletions from needing further I/O operations in order to identify the lockable ranges that those insertions and deletions modify.
    • 数据库管理系统(10)在其数据库密钥上生成有界无序索引。 在这样的索引中,叶节点(51,62)很大并被分成多个桶(52,54,56,58),其中只有一个通常在任何给定的单记录数据库操作中被访问。 根据哈希函数,叶节点中的关键值分布在叶节点的桶中。 针对扫描功能锁定的可锁定范围根据键值锁定定义,其中每个可锁定范围由数据库中存在的连续键值限定。 但是,由于可靠的范围是由桶中的关键值序列而不是在节点中定义的,所以避免了因为节点的几个桶之间的键值的散列函数分布而需要的多桶访问 。 此外,除了现有的键值之外,即使没有数据库记录包含这些键值限制,也可以使用桶的键值限制来绑定可锁定的范围。 这样可以防止最后的插入和删除需要进一步的I / O操作,以便识别这些插入和删除修改的可锁定范围。
    • 7. 发明授权
    • Database computer system with application recovery
    • 数据库计算机系统与应用程序恢复
    • US5946698A
    • 1999-08-31
    • US814808
    • 1997-03-10
    • David B. Lomet
    • David B. Lomet
    • G06F17/30
    • G06F11/1438Y10S707/99953
    • This invention concerns a database computer system and method for making applications recoverable from system crashes. The application state (i.e., address space) is treated as a single object which can be atomically flushed in a manner akin to flushing individual pages in database recovery techniques. To enable this monolithic treatment of the application, executions performed by the application are mapped to logical loggable operations which can be posted to the stable log. Any modifications to the application state are accumulated and the application state is flushed from time to time to stable storage using an atomic procedure. Applications are recovered by replaying the logged state transition operations, in the same manner that most database systems replay state transformation operations to recover database pages. This application recovery integrates with database recovery, and effectively eliminates or at least substantially reduces the need for check pointing applications. In addition, optimization techniques are described to make the read, write, and recovery phases more efficient.
    • 本发明涉及用于使应用从系统崩溃中恢复的数据库计算机系统和方法。 应用状态(即,地址空间)被视为单个对象,其可以类似于在数据库恢复技术中刷新单独页面的方式被原子地刷新。 为了实现对应用程序的这种单一处理,应用程序执行的执行映射到可以发布到稳定日志的逻辑可记录操作。 累积对应用状态的任何修改,并且使用原子程序将应用状态不时刷新到稳定存储。 通过重播记录的状态转换操作来恢复应用程序,方式与大多数数据库系统重播状态转换操作以恢复数据库页面相同。 该应用程序恢复与数据库恢复集成,并有效地消除或至少大大减少了对检查指向应用程序的需求。 此外,描述了优化技术,以使读取,写入和恢复阶段更有效率。
    • 8. 发明授权
    • Order preserving data translation
    • 订单保存数据转换
    • US5585793A
    • 1996-12-17
    • US258144
    • 1994-06-10
    • Gennady AntoshenkovDavid B. LometJames C. Murray
    • Gennady AntoshenkovDavid B. LometJames C. Murray
    • G06T9/00H03M7/30
    • G06T9/005H03M7/3088
    • In a computer system, input strings to be translated are composed of characters selected from a first alphabet. According to a predetermined criterion, a list of sub-strings is selected from the input strings to form entries in a dictionary. The entries of the dictionary are arranged according to a collating order of the first alphabet. An interval including the sub-strings of the input strings is partitioned into an all-inclusive and disjoint set of ranges. The sub-strings of the interval are arranged according to the collating order of the first alphabet, and each sub-strings of a particular range has a common prefix, the common prefix selected from the list of sub-strings. A unique encoding is assigned to each common prefix, the corresponding set of unique encodings composed of characters selected from a second alphabet. The input strings are parsed, one at the time, into a plurality of tokens, each token corresponding to a sub-string selected from the dictionary. In an output string, there is placed for each token, a corresponding one of the set of unique encodings.
    • 在计算机系统中,要翻译的输入字符串由从第一字母表中选择的字符组成。 根据预定标准,从输入字符串中选择一个子串列表,以在字典中形成条目。 字典的条目按照第一个字母表的整理顺序排列。 包括输入字符串的子串的间隔被划分成一个全包和不相交的范围集合。 间隔的子串根据第一字母表的整理顺序排列,特定范围的每个子串具有共同的前缀,从子列表中选择的公用前缀。 每个公共前缀分配唯一的编码,由从第二个字母表中选择的字符组成的对应的唯一编码集。 将输入字符串一次解析成多个令牌,每个令牌对应于从字典中选择的子串。 在输出字符串中,为每个令牌放置一组唯一编码中相应的一个。
    • 9. 发明授权
    • Distributed transaction processing using two-phase commit protocol with
presumed-commit without log force
    • 分布式事务处理使用两阶段提交协议与推定提交无日志强制
    • US5335343A
    • 1994-08-02
    • US909556
    • 1992-07-06
    • Butler LampsonDavid B. Lomet
    • Butler LampsonDavid B. Lomet
    • G06F12/00G06F9/46G06F11/14G06F15/16G06F15/177G06F15/00
    • G06F9/466G06F17/30348Y10S707/99953
    • A two-phase commit protocol for a distributed transaction processing system employs the presumed-commit configuration, with the exception that the new presumed-commit protocol coordinator needs to force-write only a "commit" log record for committed transactions, not the previous force writing of two log records. In order to provide information needed to allow the coordinator to answer inquiries from subordinate processes following a crash or loss of communications, a technique for circumscribing the set of indeterminate transactions is employed. The transactions are numbered in increasing order, identified by a transaction ID (T.sub.-- ID). The commit protocol is not allowed to begin unless the transaction ID of the committing transaction is within some preselected range of numbers starting from the highest-numbered stably-recorded transaction ID. That is, if the transaction number is too far removed from the highest TID of a stably stored log record (written to disk storage and able to survive a crash), then log records are written to disk until this condition hold. This may require writing to a disk log record for the committing transaction. Most commit transactions can, however, proceed without waiting for a disk write (forced log), and so performance is improved. A technique is disclosed for circumscribing the set of indeterminate transactions (not shown whether they committed, aborted or never started) so that information is small. It must be "permanently" retained, but the coordinator can store some of it in a cache (volatile memory) to answer inquiries.
    • 分布式事务处理系统的两阶段提交协议采用假定提交配置,除了新的推定提交协议协调器需要强制写入已提交事务的“提交”日志记录,而不是先前的强制 写两个日志记录。 为了提供所需的信息,允许协调者在通信崩溃或丢失之后回答下属进程的询问,采用限定一组不确定交易的技术。 交易按照递增顺序编号,由交易ID(T-ID)标识。 提交协议不允许开始,除非提交事务的事务ID处于从最高编号的稳定记录的事务ID开始的一些预选的数字范围内。 也就是说,如果交易号码远离稳定存储的日志记录的最高TID(写入磁盘存储并能够在崩溃中生存)太远,则将日志记录写入磁盘,直到此条件成立为止。 这可能需要写入提交事务的磁盘日志记录。 然而,大多数提交事务可以在不等待磁盘写入(强制日志)的情况下进行,因此性能得到改善。 公开了一种用于限制一组不确定事务(未示出,是否提交,中止或从未启动)的技术,使得信息很小。 它必须“永久”保留,但协调器可以将其中的一些存储在缓存(易失性存储器)中以回答查询。