  The problem of proximity full-text search is considered. If a search query
contains high-frequently occurring words, then multi-component key indexes
deliver an improvement in the search speed compared with ordinary inverted
indexes. It was shown that we can increase the search speed by up to 130 times
in cases when queries consist of high-frequently occurring words. In this
paper, we investigate how the multi-component key index architecture affects
the quality of the search. We consider several well-known methods of relevance
ranking, where these methods are of different authors. Using these methods, we
perform the search in the ordinary inverted index and then in an index enhanced
with multi-component key indexes. The results show that with multi-component
key indexes we obtain search results that are very close, in terms of relevance
ranking, to the search results that are obtained by means of ordinary inverted
indexes.
