id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
32492	Add django API for Postgres pg_trgm word_similarity, fuzzy full-text search.	Taneli	nobody	"Use case: filter queryset by an inexact substring. For example, retrieve an object with the following headline ' Dogecoin is following bitcoin in its dramatic rise' when searching for 'dogge'.
 
Currently it is possible to filter a queryset on the basis of trigram similarity between the search string and full text stored in a column. 
 {{{#!python
Author.objects.annotate(similarity=TrigramSimilarity('name', test),).filter(similarity__gt=0.3)
}}}

This is a wrapper around the '''similarity''' function of the '''pg_trgm''' extension. While it allows comparing full strings, i.e. searching for 'doge'  would find 'dogs' or 'dogge' it is useless for fuzzy searching of substrings.

{{{
SELECT similarity('dogge', 'doge');
---------
0.57

SELECT similarity('dogge', 'dogecoin is following bitcoin');
------------
0.1
}}}

'''word_similarity''' does take into account the word boundaries

{{{
SELECT word_similarity('doge', 'dogecoin is following bitcoin');
--------------
0.5
}}}

Adding a django API to '''word_similarity''' would allow for better fuzzy fulltext search without a need to use either raw SQL or external tools like elasticsearch.

"	Uncategorized	new	Uncategorized	3.1	Normal				Unreviewed	0	0	0	0	0	0