TF-IDF algorithms like BM25 do not come built in, but are straightforward to implement on top of postgres' text search: https://www.alibabacloud.com/blog/keywo

TF-IDF algorithms like BM25 do not come built in, but are straightforward to implement on top of postgres' text search: https://www.alibabacloud.com/blog/keyword-analysis-with-postgresql-cosine-and-linear-correlation-algorithms-for-text-analysis_595793 https://www.alibabacloud.com/blog/keyword-analysis-with-post... The key is you have to compute the IDF into a side table using the ts_stat function, since this is a global property (inter-document frequency) of your corpus. Once you have your IDF table you can write a ranking function based on that table.