Log System for Recovery from Database Malicious Transaction
Chen Min, Rong Chen, Wang Yun-fan · Jisuanji gongcheng · 2011
Recovery from malicious transaction has become an important method to protect database,the new recovery mechanism raises new requirement that the log file should not only record information of write operation but also the information of read operation.To fulfill the new requirement,a new log strategy is proposed,According to this strategy,the log system is designed and implemented,the system is composed by four parts: SQL statements filtrating,sensitive information setting,write log generator and read log generator.Structured Query Language(SQL) statements filtrating aims to protect the log file from malicious users.Sensitive information setting gives constraints to log record to control the size of log file.Write log generator uses triggers to records the information of write operation.Read log generator records the information of read operation via re-constructing SQL statements,creating temporary table and accessing temporary table.Experimental result shows that log system records database operations effectively,but decreases the efficiency of the whole system.