System and method for avoiding complete index tree traversals in
sequential and almost sequential index probes
    1.
    发明授权
    System and method for avoiding complete index tree traversals in sequential and almost sequential index probes 失效
    用于避免在顺序和几乎顺序的索引探针中完整的索引树遍历的系统和方法

    公开(公告)号:US5748952A

    公开(公告)日:1998-05-05

    申请号:US438558

    申请日:1995-05-10

    IPC分类号: G06F17/30

    摘要: The present invention provides a system and method for utilizing the proximity of keys in sequential or near sequential index probes to avoid complete index tree traversal. Page information from three pages (LAST, PARENT and NEXT) are stored in separate information fields within an Index Lookaside Buffer. The LAST information field contains information on the most recent leaf page accessed during an index probe in a read key or an insert key operation, the PARENT information field contains information on the parent page of the most recently accessed leaf page described in the LAST information field, and the NEXT information field contains information on the most recent leaf page accessed during a fetch-next key or delete key operation. On a subsequent index probe, the LAST, NEXT and PARENT information fields are sequentially analyzed to determine if the search key is contained within the leaf page described by the LAST or NEXT information fields or if the search key is contained within one of the leaf pages pointed to by the parent page described by the PARENT information field. If none of the LAST, NEXT or PARENT information fields identify the leaf page containing the search key then the default root-to-leaf traversal would commence.

    摘要翻译: 本发明提供一种用于利用顺序或近序列索引探针中的密钥接近以避免完整的索引树遍历的系统和方法。 来自三个页面(LAST,PARENT和NEXT)的页面信息存储在索引后备缓冲区中的单独的信息字段中。 LAST信息字段包含在读取键或插入键操作期间在索引探测期间访问的最新叶子页面的信息,PARENT信息字段包含在LAST信息字段中描述的最近访问的叶子页面的父页面上的信息 ,并且NEXT信息字段包含在获取下一个键或删除键操作期间访问的最新叶子页面的信息。 在随后的索引探针中,顺序地分析LAST,NEXT和PARENT信息字段以确定搜索关键字是否包含在由LAST或NEXT信息字段描述的叶子页内,或者如果搜索关键字包含在叶子页之一内 由PARENT信息字段描述的父页指向。 如果LAST,NEXT或PARENT信息字段中没有一个标识包含搜索关键字的叶子页面,则将开始默认的从根到叶遍历。

    Computer program product for avoiding complete index tree traversals in
sequential and almost sequential index probes
    2.
    发明授权
    Computer program product for avoiding complete index tree traversals in sequential and almost sequential index probes 失效
    用于避免在顺序和几乎顺序的索引探针中完整的索引树遍历的计算机程序产品

    公开(公告)号:US5845274A

    公开(公告)日:1998-12-01

    申请号:US471509

    申请日:1995-06-06

    IPC分类号: G06F17/30

    摘要: The present invention provides a system and method for utilizing the proximity of keys in sequential or near sequential index probes to avoid complete index tree traversal. Page information from three pages (LAST, PARENT and NEXT) are stored in separate information fields within an Index Lookaside Buffer. The LAST information field contains information on the most recent leaf page accessed during an index probe in a read key or an insert key operation, the PARENT information field contains information on the parent page of the most recently accessed leaf page described in the LAST information field, and the NEXT information field contains information on the most recent leaf page accessed during a fetch-next key or delete key operation. On a subsequent index probe, the LAST, NEXT and PARENT information fields are sequentially analyzed to determine if the search key is contained within the leaf page described by the LAST or NEXT information fields or if the search key is contained within one of the leaf pages pointed to by the parent page described by the PARENT information field. If none of the LAST, NEXT or PARENT information fields identify the leaf page containing the search key then the default root-to-leaf traversal would commence.

    摘要翻译: 本发明提供一种用于利用顺序或近序列索引探针中的密钥接近以避免完整的索引树遍历的系统和方法。 来自三个页面(LAST,PARENT和NEXT)的页面信息存储在索引后备缓冲区中的单独的信息字段中。 LAST信息字段包含在读取键或插入键操作期间在索引探测期间访问的最新叶子页面的信息,PARENT信息字段包含在LAST信息字段中描述的最近访问的叶子页面的父页面上的信息 ,并且NEXT信息字段包含在获取下一个键或删除键操作期间访问的最新叶子页面的信息。 在随后的索引探针中,顺序地分析LAST,NEXT和PARENT信息字段以确定搜索关键字是否包含在由LAST或NEXT信息字段描述的叶子页内,或者如果搜索关键字包含在叶子页之一内 由PARENT信息字段描述的父页指向。 如果LAST,NEXT或PARENT信息字段中没有一个标识包含搜索关键字的叶子页面,则将开始默认的从根到叶遍历。

    Transaction consistent content replication
    4.
    发明授权
    Transaction consistent content replication 有权
    事务一致的内容复制

    公开(公告)号:US08086566B2

    公开(公告)日:2011-12-27

    申请号:US12338209

    申请日:2008-12-18

    IPC分类号: G06F17/30

    CPC分类号: G06F17/30306

    摘要: Exemplary embodiments of the present invention relate to methodologies, computer program products and systems for the support of content replication, wherein transaction-level data replication consistency is guaranteed. Further, the exemplary methodologies of the present invention can be implemented while incurring little or no additional I/O overhead.

    摘要翻译: 本发明的示例性实施例涉及用于支持内容复制的方法学,计算机程序产品和系统,其中保证事务级数据复制一致性。 此外,本发明的示例性方法可以在很少或没有额外的I / O开销的情况下实现。

    Order preserving run length encoding with compression codeword
extraction for comparisons

    公开(公告)号:US5629695A

    公开(公告)日:1997-05-13

    申请号:US466918

    申请日:1995-06-06

    IPC分类号: G06F17/30

    摘要: The present invention provides a system and method for the dictionary ordering of keys after expansion, compression and concatenation of their key parts. After each key part has been expanded through padding, each substring of identical characters of length greater than or equal to three is compressed through run-length encoding algorithm. The substring is replaced by the sequence character, a compression identifying character and a number identifying the number of characters being replaced. After compression and the subsequent concatenation, the keys are compared character by character. At the first instance of a miscomparison, the comparison scheme performs a normal dictionary ordering if neither of the characters are part of a compression sequence. If a character at the point of miscomparison is part of a compression sequence then an ordering decision is made based on the compression character, the length of the compressed substring and the character following the compressed substring.

    Order preserving run length encoding with compression codeword
extraction for comparisons
    7.
    发明授权
    Order preserving run length encoding with compression codeword extraction for comparisons 失效
    订单保留运行长度编码与压缩码字提取进行比较

    公开(公告)号:US5619199A

    公开(公告)日:1997-04-08

    申请号:US434775

    申请日:1995-05-04

    IPC分类号: G06F17/30

    摘要: The present invention provides a system and method for the dictionary ordering of keys after expansion, compression and concatenation of their key parts. After each key part has been expanded through padding, each substring of identical characters of length greater than or equal to three is compressed through run-length encoding algorithm. The substring is replaced by the sequence character, a compression identifying character and a number identifying the number of characters being replaced. After compression and the subsequent concatenation, the keys are compared character by character. At the first instance of a miscomparison, the comparison scheme performs a normal dictionary ordering if neither of the characters are part of a compression sequence. If a character at the point of miscomparison is part of a compression sequence then an ordering decision is made based on the compression character, the length of the compressed substring and the character following the compressed substring.

    摘要翻译: 本发明提供了一种在关键部件的扩展,压缩和级联之后对键进行字典排序的系统和方法。 在通过填充扩展每个关键部分之后,通过游程编码算法压缩长度大于或等于3的相同字符的每个子字符串。 子字符串由序列字符替换,压缩识别字符和标识要替换的字符数的数字。 经过压缩和随后的级联,按键逐个比较。 在错误比较的第一个实例中,如果两个字符都不是压缩序列的一部分,则比较方案执行正常的字典排序。 如果错误点处的字符是压缩序列的一部分,则基于压缩字符,压缩子字符串的长度和压缩子字符串之后的字符进行排序决定。