一种Symbian S60数据库应用中的文本压缩方法

为了提高Symbian S60数据库中文本数据存储的效率,同时使数据库应用具有良好的响应速度,在研究该类数据库的特点和"字典码"压缩算法的基础上,提出通过提取隐含在"字典码"压缩算法压缩的文件中的字典并独立存储和维护,实现对数据库记录级的文本压缩。该方法只有在用户用到数据库记录数据时,相应记录中被压缩的数据才被解压缩,因此数据库的响应速度快,内存占用也更少,开始运行软件时数据库加载也更快。该方法在数据记录短,文本数据量大的数据库应用中更具有优势。

A TEXT COMPRESSION METHOD IN SYMBIAN S60 DATABASE APPLICATIONS

To improve text data storage efficiency for Symbian S60 database and meanwhile to ensure appropriate response speed for database applications,on the basis of researches on features of that kind of database as well as the "dictionary coder" compression algorithm,it is proposed to extract the dictionary of the compressed file that is concealed in "dictionary coder" compression algorithm for independent storage and maintenance,so that the database record level text compression is realized.The method ensures that only when users address database record data,the compressed data in corresponding records can be decompressed.Therefore the database responses at an appropriate speed,consumes less memory and loads the database faster when starting up the software.The method is more advantageous in database applications where there are shorter data records or heavier text data burden.