Patent ID: 7467130
Filing Date: 2008-12-16
Classification: G06F,Y10S

Abstract:
1. A method of connecting a plurality of table-format data, each table-format data being expressed as a record array containing an entry and an entry value included in the entry, and converting the connected table-format data as join tables to a tree structure, the method comprising the steps of: (a) dividing each table-format data into one or more information blocks, each information block containing a value list in which entry values belonging to specified entries are stored in order of entry value numbers corresponding to the entry values and a pointer array in which pointer values indicating the entry value numbers are stored in univocal order of record numbers; (b) selecting two table-format data in which an entry is made common; (c) finding an entry that is made common in the selected two table-format data; (d) determining table-format data on which default sorting order is reflected, as master table-format data, of specified information blocks, and determining other table-format data as slave table-format data; (e) in the case where value lists contained in the specified information blocks are equalized with each other in the selected two table-format data, generating a master-side projection array for the master table-format data, wherein the master-side projection array is formed by summing up the number of times of duplication of each line, and generating a master-side ordered set for the master table-format data and also a slave-side projection array for the slave table-format data, wherein the slave-side projection array is formed by summing up the number of times of duplication of each line in a join table, and generating a slave-side ordered set for the slave table-format data, wherein the slave-side ordered set is sorted by entry used as a key for joining; (f) repeating steps (b), (c), (d) and (e), and when there is a table which is joined with the slave table-format data of the two table-format data, using the slave table-format data as master table-format data; (g) generating a reverse mapping array between one join table and a subsequent join table using the master-side projection array as an original array for the subsequent join table; (h) selecting one of the table-format data connected by joining to be a root, and determining depth of each table-format data in accordance with the connection of the table-format data; (i) securing an area for a tree description table having as a value a combination of the depth and a record number; (j) initializing a current depth to the depth of the table-format data to be the root of the tree structure; (k) specifying a record in the master-side ordered set for the join table corresponding to the current depth, and arranging a value indicating the record together with the depth into the area for the tree description table; (l) acquiring an element in the master-side ordered set for the subsequent join table by tracing the slave-side projection array and the slave-side ordered set corresponding to the master-side ordered set for the join table on the current depth, as well as, when present, the reverse mapping array and the master-side projection array for the subsequent join table; and (m) repeating steps (k) and (l) with sequentially searching in the direction of the depth until no further elements are acquired.