×

Method of recursively deriving and storing data in, and retrieving recursively-derived data from, a computer database system

  • US 5,546,571 A
  • Filed: 02/16/1993
  • Issued: 08/13/1996
  • Est. Priority Date: 12/19/1988
  • Status: Expired due to Term
First Claim
Patent Images

1. In a computerized database system, a method of deriving data and storing the derived data in a memory of the computer, the method comprising:

  • deriving new items of data for storage in the memory by iteratively evaluating a database query that receives itself as an argument a plurality of times according to a recursive relation;

    associating storage locations in the memory with a plurality of hierarchical iteration levels, one such level corresponding with each iteration of the recursive relation performed by the computer to derive the new data items;

    storing all data items derived during a given iteration in locations associated with the corresponding iteration level;

    reserving a plurality of memory locations to form a sequence set having a plurality of leaf node locations arranged sequentially to define a bottom index level of an index structure;

    for each newly derived data item, entering in a leaf node location of the sequence set a cross-reference between a pointer to that data item, a key value which uniquely identifies that data item, and the iteration level associated with that data item;

    reserving a plurality of memory locations to form an index set having a plurality of non-leaf node locations arranged hierarchically to define a plurality of index levels above the bottom index level of the index structure, each level having fewer nodes than the level beneath it;

    assigning each node a range of the key values of the sequence set such that all of the nodes on any level together encompass all of said key values, each range encompassed by a node is included in the range encompassed by a node on the next higher level, and each node provides for any key value within its range an access path to a node on the next lower level having said key value within its range;

    reserving a plurality of memory locations to form an iteration level index to provide a reference between each iteration level and a data item associated with that level; and

    linking the data items associated with each iteration level by storing references in the memory between the data items.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×