Prefix matching should not omit stop words, as matching lexemes may legitimately begin with stop words.
# select to_tsquery('english', 'over:*') @@ to_tsvector('english', 'overhaul'); NOTICE: text-search query contains only stop words or doesn't contain lexemes, ignored ?column? ---------- f (1 row)
I noticed this after implementing interactive, incremental search in an application. As the user typed "overhaul," with each successive character executing a search, "ove" and "overh" matched a particular document, but "over" did not.
Big thanks for the reporting!
I am not sure that it is a bug. I think this is a way how to_tsquery conversion work: stopwords first then template processing.
If you want to process successive characters typing, you can use casting to tsvector type until input is not finished
'over:*'::tsquery;
and when the user finishes input then process the result via to_tsquery with stop words.
if we do to_tsquery in a way you described I expect it will never apply the stop-word filter on templated input as it can not be compared to stop words.
