The Research On Coal Quality File Management System Based On Mixed Full-text Index

The rapid development of information technology industry has greatly changed the way of people's access to information and use. People is more willing to disseminate information through electronic documents. In view of the specific field of coal, all kinds of coal quality electronic files present explosive growth. In the face of the vast ocean of information, how to help users to effectively manage coal quality file information, and how to help users quickly identify and extract useful information, are what coal enterprises facing today.Aiming at the faster querying of coal quality file, this paper puts forward a kind of hybrid index based on inverted table and B+ tree. The inverted index is relatively simple to implement. It perform better on phrase query and retrieve speed. But it is not sensitive for the digital data, so it can't quickly and accurately retrieve the relevant information on digital data's retrieval. While the B+ tree index can achieve random or sequential data processing.Because all data is stored in B+ tree's leaf nodes, and itself is ordering that makes it very suitable for digital data index. Through analysis of characteristics of the coal quality files can be drawn: the data type of the coal quality files mainly has character type and digital type.Mixed full-text indexing structure is proposed in this paper, combined with the advantages of inverted index and B+ tree index, is to establish a hierarchical data index for coal quality file.Firstly, according to coal quality files' data type established B+ tree index. Secondly,according to the different data types established the corresponding index, which can be separated as two parts: the data type is character then created the inverted index for it,otherwise created the B+ tree index for it.Designed and implemented a coal quality file management system. This system used the current mainstream three frameworks(Spring, Struts2, Hibernate) technology, combined with Oracle database, realized several functional modules. Like coal quality files' basicinformation management, users management, file upload, file download, file sharing,multidimensional classification of files, file encryption, file decryption, file retrieval and so on. Among them, the security control module presented a file operation records tracing scheme. It will save all confidential files using records and can get every corresponding records item. Monitor and analyze some elements of the records item(read and write operations or common use host IP), and give warnings for possible security risks to ensure the security of confidential files.The system's functional tests show that it is running well. The experimental results of the mixed full-text index show that compared with the simple inverted index or B+ tree index,there is obvious advantages on index creating occupy and retrieval time performance.