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公开(公告)号：US06778985B1
公开(公告)日：2004-08-17
申请号：US10278898
申请日：2002-10-24
IPC分类号： G06F1730
CPC分类号： G06F17/30595 , G06F17/3061 , Y10S707/99937 , Y10S707/99943 , Y10S707/99944
摘要： A method and apparatus is disclosed for implementing descending indexes in a database management system. A key value to be inserted within an index is decomposed into individual data bytes, such as an integer character value, that make up the key value and dictate the location where the key value will be inserted relative to other key values. A first function is applied to the data sequences in order to generate a reversed key value having reversed sorting properties. The reversed key values are then inserted into the index. The resulting index thus contains key values that are sorted in descending order. Additionally, indexes may be created on multiple key columns, with the sub_keys being independently sorted in either ascending or descending order. The present invention also discloses transformations that may be performed by a server in order to properly interpret statements that require the creation of standard or functional indexes in descending order.
摘要翻译： 公开了一种用于在数据库管理系统中实现降序索引的方法和装置。 要插入到索引中的键值被分解为单个数据字节，例如整数字符值，它构成键值，并且指定相对于其他键值插入键值的位置。 将第一功能应用于数据序列，以便产生具有反向排序特性的反转键值。 然后将反转的键值插入到索引中。 因此，生成的索引包含按降序排序的键值。 另外，可以在多个键列上创建索引，其中子键以升序或降序独立排序。 本发明还公开了可以由服务器执行的转换，以便适当地解释需要按降序创建标准或功能索引的语句。
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公开(公告)号：US06496830B1
公开(公告)日：2002-12-17
申请号：US09330071
申请日：1999-06-11
IPC分类号： G06F1730
CPC分类号： G06F17/30595 , G06F17/3061 , Y10S707/99937 , Y10S707/99943 , Y10S707/99944
摘要： A method and apparatus is disclosed for implementing descending indexes in a database management system. A key value to be inserted within an index is decomposed into individual data bytes, such as an integer character value, that make up the key value and dictate the location where the key value will be inserted relative to other key values. A first function is applied to the data sequences in order to generate a reversed key value having reversed sorting properties. The reversed key values are then inserted into the index. The resulting index thus contains key values that are sorted in descending order. Additionally, indexes may be created on multiple key columns, with the sub_keys being independently sorted in either ascending or descending order. The present invention also discloses transformations that may be performed by a server in order to properly interpret statements that require the creation of standard or functional indexes in descending order.
摘要翻译： 公开了一种用于在数据库管理系统中实现降序索引的方法和装置。 要插入到索引中的键值被分解为单个数据字节，例如整数字符值，它构成键值，并且指定相对于其他键值插入键值的位置。 将第一功能应用于数据序列，以便产生具有反向排序特性的反转键值。 然后将反转的键值插入到索引中。 因此，生成的索引包含按降序排序的键值。 另外，可以在多个键列上创建索引，其中子键以升序或降序独立排序。 本发明还公开了可以由服务器执行的转换，以便适当地解释需要按降序创建标准或功能索引的语句。
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公开(公告)号：US07908267B2
公开(公告)日：2011-03-15
申请号：US10929065
申请日：2004-08-26
申请人： Robert J. Jenkins, Jr. , Adiel Yoaz
发明人： Robert J. Jenkins, Jr. , Adiel Yoaz
CPC分类号： G06F17/30463
摘要： An approach for using functional indexes as a primary filter is provided. A database query that contains a reference to a column of a table, but does not contain any reference to a functional index based on that column, is received by a database server. The database server adds to the database query a reference to the functional index on the column. The database server determines if the database query should be executed using the functional index. If the database server determines that the database query should be executed using the functional index, then the database query is executed with the functional index. If the database server determines that the database query should not be executed using the functional index, then data that indicates that the functional index is not to be evaluated when the database query is executed is stored.
摘要翻译： 提供了使用功能索引作为主要过滤器的方法。 包含对表的列的引用，但不包含对基于该列的功能索引的任何引用的数据库查询由数据库服务器接收。 数据库服务器向数据库查询添加对列的功能索引的引用。 数据库服务器确定是否应使用功能索引执行数据库查询。 如果数据库服务器确定使用功能索引执行数据库查询，则使用功能索引执行数据库查询。 如果数据库服务器确定不应使用功能索引执行数据库查询，则存储指示在执行数据库查询时不评估功能索引的数据。
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4.发明授权
公开(公告)号：US5899993A
公开(公告)日：1999-05-04
申请号：US694350
申请日：1996-08-07
IPC分类号： G06F17/30
CPC分类号： G06F17/30371 , Y10S707/99939 , Y10S707/99945
摘要： A method and apparatus are disclosed for enabling a constraint without prohibiting updates to the constrained data during the validation portion of the enablement process. A constraint is first enforced. While the constraint is being enforced, the pre-existing data are inspected to determine whether the constraint is valid. Because the constraint is in force for all changes to the data during the validation process, the constraint will be enabled if the pre-existing data conforms with the constraint. A serialization value is stored in the constraint definition. Whenever the constraint definition is changed, the serialization value is changed. The serialization value of a constraint definition is recorded before validating the constraint. After validating the constraint, the serialization value in the constraint definition is compared to the recorded serialization value to determine whether the constraint definition was changed during the validation process.
摘要翻译： 公开了一种用于实现约束的方法和装置，而不禁止在启用过程的验证部分期间更新约束数据。 约束首先被执行。 在执行约束的同时，检查预先存在的数据以确定约束是否有效。 因为约束在验证过程中对数据的所有更改都有效，所以如果预先存在的数据符合约束条件，则约束将被启用。 序列化值存储在约束定义中。 每当约束定义被改变时，序列化值被改变。 在验证约束之前记录约束定义的序列化值。 在验证约束之后，将约束定义中的序列化值与记录的序列化值进行比较，以确定在验证过程中约束定义是否已更改。
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公开(公告)号：US06490610B1
公开(公告)日：2002-12-03
申请号：US08866842
申请日：1997-05-30
IPC分类号： G06F900
CPC分类号： G06F11/2046 , G06F11/2028 , G06F11/2038 , H04L41/0663 , H04L43/0811 , H04L67/14 , H04L69/40 , Y10S707/99953
摘要： A method and system for recovering after failure of a first server to which a client was connected for accessing a resource is provided. When it is detected that a connection between the first server and the client has failed, the client is automatically connected with a second server that has access to the resource. After automatically connecting the client, the client accesses the resource through the second server. The client stores information about the state of the session with the first server so that processing can continue where it left off after the client connects with the second server. The client may be pre-connected to the second server prior to the failure of the first server to reduce the latency caused by switching in response to a failure. The second server may be configured to pre-parse the commands that the client issues to the first server to further reduce the latency associated with switching to the second server.
摘要翻译： 提供了一种用于在连接了客户机以访问资源的第一服务器故障之后恢复的方法和系统。 当检测到第一服务器和客户端之间的连接发生故障时，客户机将自动连接到可访问该资源的第二个服务器。 客户端自动连接后，客户端通过第二台服务器访问资源。 客户端存储有关第一台服务器的会话状态的信息，以便在客户端与第二台服务器连接后，处理可以继续停止。 在第一服务器发生故障之前，客户端可能被预连接到第二服务器，以减少由于故障而导致的切换所引起的等待时间。 第二服务器可以被配置为预先解析客户端向第一服务器发出的命令，以进一步减少与切换到第二服务器相关联的延迟。
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