How to merge sort records in a high efficiency with a trie tree structure, apparatus and computer program

摘要

A first record group and a second record group having a tree structure are merge-sorted. The first record group and the second record group are acquired, and depth information indicative of the hierarchical depth of the tree structure is attached as metadata to key information on each node of each record included in the acquired first record group and second record group. The depth information is compared in preference to the key information to perform merge sort sequentially.