公开(公告)号：US5557791A

公开(公告)日：1996-09-17

申请号：US325942

申请日：1994-10-19

申请人： Josephine M. Cheng ,  Chandrasekaran Mohan ,  Mir H. Pirahesh

发明人： Josephine M. Cheng ,  Chandrasekaran Mohan ,  Mir H. Pirahesh

IPC分类号： G06F17/30

CPC分类号： G06F17/30498 ,  Y10S707/99932

摘要： A computer database system utilizes a method for performing a right outer join of database tables without sorting the inner table (T.sub.2). The processing of each tuple in the outer table (T.sub.1) includes the preservation in the joint output of all tuples in T.sub.2 which are in its responsibility region. The initialization step of the process preserves in the join output all of the tuples in T.sub.2 which have column set values less than the lowest column set value in T.sub.1, i.e. the first tuple in T.sub.1, since T.sub.1 is sorted or accessed using a sorted index. The responsibility region for tuples in T.sub.1, other than the last tuple, is defined as those tuples which have column set values less than the column set value for the next tuple in T.sub.1 and greater than or equal to the column set value for the current T.sub.1 tuple. The last tuple in T.sub.1 must preserve all of the tuples in T.sub.2 which have not already been preserved in T.sub.2, i.e. all tuples greater than or equal to its column set value. If T.sub.1 has duplicate values for the column set value, only the last one preserves the associated T.sub.2 tuples. Additional methods for parallel execution of the outer join methods and methods for applying the outer join methods to subqueries (i.e., an All (or universal) Right Join (ARJOIN) and an Existential Right Join (ERJOIN)) are described.

摘要翻译： 计算机数据库系统利用用于执行数据库表的右外连接的方法，而不排序内表（T2）。 外表（T1）中每个元组的处理包括在其责任区域的T2中所有元组的联合输出中的保存。 该进程的初始化步骤在连接输出中保留所有T2中的元组，它们的列设置值小于T1中的最低列设置值，即T1中的第一个元组，因为使用排序索引对T1进行排序或访问。 T1中的元组的责任区域除了最后一个元组之外，被定义为具有小于T1中下一个元组的列设置值的列设置值大于或等于当前T1的列设置值的元组 元组 T1中的最后一个元组必须保留T2中尚未保存在T2中的所有元组，即大于或等于其列设置值的所有元组。 如果T1具有列设置值的重复值，则只有最后一个值保留关联的T2元组。 描述了用于并行执行外连接方法和将外连接方法应用于子查询（即，全（或通用）右连接（ARJOIN）和存在右连接（ERJOIN））的附加方法。

公开(公告)号：US5241648A

公开(公告)日：1993-08-31

申请号：US479523

申请日：1990-02-13

申请人： Josephine M. Cheng ,  Donald J. Haderle ,  Richard W. Hedges ,  Balakrishna R. Iyer ,  Chandrasekaran Mohan ,  Yun Wang

发明人： Josephine M. Cheng ,  Donald J. Haderle ,  Richard W. Hedges ,  Balakrishna R. Iyer ,  Chandrasekaran Mohan ,  Yun Wang

IPC分类号： G06F12/00 ,  G06F17/30

CPC分类号： G06F17/30498 ,  Y10S707/99937

摘要： Results of a relational data base management system are joined in a process requiring, first, existence of an index on the join columns of the inner table, and, second, ordering on the join column of the first table. First, the index on the inner table's join column is scanned for rows of the inner table having join column values matching such values of rows in the outer table. This is done in a single pass through the outer table. Next, a temporary work table containing the identifiers of inner table rows having join column values matching those of the outer table is produced by concatenating the row identifiers to their matching outer table rows. Following this, the temporary work table is ordered by the identifiers. Last, the identifier list of inner table rows is used to retrieve the corresponding rows of the inner table. All predicates local to the inner table are applied to the retrieved rows, and those satisfying these local predicates are combined with their matching outer table rows and returned to the user.

公开(公告)号：US4833604A

公开(公告)日：1989-05-23

申请号：US818432

申请日：1986-01-13

申请人： Josephine M. Cheng ,  Nicholas V. Nomm ,  Jay A. Yothers

发明人： Josephine M. Cheng ,  Nicholas V. Nomm ,  Jay A. Yothers

IPC分类号： G06F12/00 ,  G06F9/06 ,  G06F9/445 ,  G06F12/02

CPC分类号： G06F9/44521

摘要： A two-pass method for relocating a set of linked control blocks stored away on a persistent medium after a first pass and then rewritten into internal memory of a computing facility during second and subsequent passes each time an application to which the control blocks are bound is executed. The first pass involves path following and coloring pointers affected by the relocation, mapping discontiguously located blocks into a linear address space, changing affected control blocks to location offsets, and writing out the linked control blocks to DASD store. Upon the second pass, virtual addresses are substituted for the offsets upon rewriting of the control blocks to internal memory.

摘要翻译： 一种用于在第一次通过之后将一组存储在永久介质上的链接控制块重定位并且随后在第二次和随后的遍历期间被重新写入计算设备的内部存储器的两遍方法中， 执行。 第一遍涉及由重定位影响的路径跟踪和着色指针，将不连续定位的块映射到线性地址空间中，将受影响的控制块改变为位置偏移，并将链接的控制块写入DASD存储。 在第二次通过时，在将控制块重写到内部存储器时，将虚拟地址替换为偏移量。