关键词: 增量提取, MD5算法, HASH算法, 线性扫描

Abstract: To achieve rapid incremental extraction of database, an algorithm which is blended MD5 in HASH linear scanning to obtain increment is put forward based on analyzing the traditional incremental extraction. Each record in database can be seen as a character string and it can be generated into hash table as duplicate record, which is explored in hash table through traditional record to obtain increment and decrease frequency of comparison. Meanwhile, the fingerprint of each record can be generated with using MD5 algorithm, which reduces the length of character string in every HASH algorithm and comparison and improves efficiency. This algorithm is applicably tested in ORACLE database and the result shows that it is improved on calculative efficiency at a large extent compared with traditional algorithm.

Key words: incremental extraction, MD5 algorithm, HASH algorithm, linear scan