Boosting increases or decreases the impact of a specific query by multiplying its contribution to the overall BM25 score.

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Constant Boosting

To boost a query, cast the query to the boost type. In this example, the shoes query is weighted twice as heavily as the footwear query. 
SELECT id, paradedb.score(id), description, category
FROM mock_items
WHERE description ||| 'shoes'::boost(2) OR category ||| 'footwear'
ORDER BY score DESC
LIMIT 5;
boost takes a numeric value, which is the multiplicative boost factor. It can be any floating point number between -2048 and 2048. Query builder functions can also be boosted: 
SELECT id, description, category, paradedb.score(id)
FROM mock_items
WHERE description @@@ pdb.regex('key.*')::boost(2)
ORDER BY score DESC
LIMIT 5;
Boost can be used in conjunction with other type casts, like fuzzy: 
SELECT id, description, category, paradedb.score(id)
FROM mock_items
WHERE description ||| 'shose'::fuzzy(2)::boost(2)
ORDER BY score DESC
LIMIT 5;

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Boosting by Field

The following query boosts the score of each row by multiplying it by the row’s rating. This means that items with the same score but a higher rating will score higher overall. 
SELECT id, description, rating, paradedb.score(id) * rating as score
FROM mock_items
WHERE description ||| 'shoes'
ORDER BY score DESC
LIMIT 5;
Ordering by paradedb.score(id) * rating is less performant than ordering by just paradedb.score(id) over large tables.