Perhaps the following articles can be of assistance:
Is it possible to reset the User Votes rating on a - CA Knowledge
What is FAQ rating and How to change the FAQ ratin - CA Knowledge
You can actually run the following command to see the SQL we use when performing any operation in SDM:
pdm_logstat -f sqlclass.c MILESTONE
Then rate a document and you should see something similar to the line below written to your sdtlog:
(UPDATE SKELETONS SET HITS = ? , USER_SLV_CNT = ? , VOTE_COUNT = ? , AVG_RATING = ? , SD_ACCEPTED_HITS = ? , LAST_HIT_DATE = ? , LAST_VOTE_DATE = ? WHERE ID = ?) Input (<HITS:int>3|<USER_SLV_CNT:int>1|<VOTE_COUNT:int>1|<AVG_RATING:float>2|<SD_ACCEPTED_HITS:int>0|<LAST_HIT_DATE:int>1494963634|<LAST_VOTE_DATE:int>1494963688|<ID:int>400001)
So based on the above, the FAQ Rating is being calculated by HITS, USER_SLV_CNT, VOTE_COUNT, AVG_RATING, SD_ACCEPTED_HITS from the skeletons table.
You just have to play around with these fields to increase the FQA ratings to push your required documents into the TOP solutions.