I am building a plugin for my web site to find relevant data from the database. I have used an sql query to fetch the relevant data by using MATCH() and AGAINST() commands. But could not get much relevant data. I want a method that is purely PHP programmed which will search relevant data and rate it and show the best having much relevancy. Can any one suggest me the the best?

Could you explain what you mean by "relevant data"? Maybe give an example of what you're trying to do? You might want to look into full-text searches in MySQL.

You should do as much processing and searching within MySQL as possible, because it is much quicker than selecting everything and searching in PHP. Use PHP to build queries that are as specific as possible, and let MySQL do the magic searching, grouping and sorting.