Hi. Mediawiki 1.38.2 and CirrusSearch generate Elastic queries using "query_string". How do I make Cirrus use "match_phrase_prefix" instead" ?
This will allow me to find page using partial keywords: Example "Cirr" will return pages with "Cirrus" inside.
Any ideas ? Thanks.
Within cirrus we don't have anything that directly supports match_phrase_prefix. We generally avoid this style of query as it provides queries that give unexpected outputs that can change depending on which replicas of the index it lands on. In particular there is no guarantee with match_phrase_prefix that "cirr" will return pages with "Cirrus" inside of them. Instead it will look at term dictionaries and select a number of words somewhat arbitrarily that start with cirr and then search for those words. Depending on the exact term statistics in the replica it lands on this can choose a different set of words to search for when repeating the same query.
While I would generally suggest avoiding it, the existing query_string queries do support this style of query. You can achieve the same functionality by appending a *, such as cirr*
Thanks for your anser.
It's a Swiss-French medical Wiki used by doctors, with a lot of long words. Our basic users don't know Elatic tricks, like "*" or "~".
I.E: "Prostatectomie", should be found by juste by entering "Prostat"
So if we cannot use match_phrase_prefix, can we put the final "*" by default in all search with Cirrus?
To customize the main full text search query you can implement your own \CirrusSearch\Query\FullTextQueryBuilder implementation and register it in the wgCirrusSearchFullTextQueryBuilderProfiles config var, see some examples for other builder profiles here. Then you can activate this new profile as the default by setting wgCirrusSearchFullTextQueryBuilderProfile to its name.
You have some examples of how to implement a FullTextQueryBuilder here.
Note that doing this is not very trivial but this is I think the only way to achieve what you want without teaching your users to use the search syntax.
