Hi all,
I am working on an application that must deal with ranking on highly dynamic metadata. For example, suppose I want to provide ranking based on the number of downloads of hit documents. A user may log-in to the system and send a query, which will be answered by Lucene in a traditional way. The relevant documents will be scored and ranked, based on default Lucene scoring functions. In addition, the system wants to support users with the "popularity" ranking facility. The number of downloads for a document may continue to increase, even during a query. It will incur much overhead if we put the "popularity" as a field in the Lucene index (delete and insert the document when an update happens). Instead, we choose to store such information in a database, with document identifiers linking database records back to the index. This setting, however, creates a ranking problem. It is not efficient to send each hit document identifier to the database as a SQL query to obtain the download popularity information. It will be good to have the mechanism to link database records directly with Lucene indices, for which a query can retrieve corresponding records from the database at the querying time. We are very interested to know if there is some open source toolkits or libraries to do the dirty-works. Of course, we also want to know other alternative solutions to meet our ends. Best Regards, Joaquin
