# Question about Phrase Suggester's prefix\_len **URL:** \ **Category:** Elasticsearch\ **Created:** [October 18, 2013, 2:05pm UTC](https://discuss.elastic.co/t/question-about-phrase-suggesters-prefix-len/14016 "2013-10-18T14:05:15Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![nik9000](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nik9000/32/44947_2.png) [@nik9000](https://discuss.elastic.co/u/nik9000)\ **Post date:** [October 18, 2013, 2:05pm UTC](https://discuss.elastic.co/t/question-about-phrase-suggesters-prefix-len/14016/1 "2013-10-18T14:05:15Z")
According to [http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-phrase.htmlraising](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-phrase.htmlraising) prefix\_len should improve performance and lowering it will make things slower. If I set it to 0, is that really going to kill performance? I've got someone complaining that "chokolade" doesn't correct to "schokolade". As a someone who's highschool German faded long ago from my memory I'd pronounce both words the same way. Nik -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![simonw\_2](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/simonw_2/32/1130_2.png) [@simonw\_2](https://discuss.elastic.co/u/simonw_2)\ **Post date:** [October 18, 2013, 7:00pm UTC](https://discuss.elastic.co/t/question-about-phrase-suggesters-prefix-len/14016/2 "2013-10-18T19:00:45Z")
Nick I think you will suffer much from setting it to 0 but give it a try. To do what you want to do have a second candidate generator that uses a reverse filter with a reasonable prefix len? simon On Friday, October 18, 2013 4:05:15 PM UTC+2, Nikolas Everett wrote: > According to > [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-phrase.htmlraising) prefix\_len should improve performance and lowering it will make > things slower. If I set it to 0, is that really going to kill > performance? I've got someone complaining that "chokolade" doesn't correct > to "schokolade". As a someone who's highschool German faded long ago from > my memory I'd pronounce both words the same way. > > Nik -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![nik9000](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nik9000/32/44947_2.png) [@nik9000](https://discuss.elastic.co/u/nik9000)\ **Post date:** [October 21, 2013, 12:33pm UTC](https://discuss.elastic.co/t/question-about-phrase-suggesters-prefix-len/14016/3 "2013-10-21T12:33:43Z")
I'm not sure I'll get a chance to work on this soon but I'll remember to try the reverse filters when I can. Is the goal of the prefix len just to cut down on the number of candidates or to improve the locality of lookups in the term statistics? Actually, I imagine both. Thanks! Nik On Fri, Oct 18, 2013 at 3:00 PM, simonw [simon.willnauer@elasticsearch.com](mailto:simon.willnauer@elasticsearch.com)wrote: > Nick I think you will suffer much from setting it to 0 but give it a try. > To do what you want to do have a second candidate generator that uses a > reverse filter with a reasonable prefix len? > > simon > > On Friday, October 18, 2013 4:05:15 PM UTC+2, Nikolas Everett wrote: > > > According to [Elasticsearch Platform — Find real-time answers at scale | Elastic](http://www.elasticsearch.org/**guide/en/elasticsearch/)\*\* > > reference/current/search-\*\*suggesters-phrase.html[http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-phrase.html](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-phrase.html)raising prefix\_len should improve performance and lowering it will make > > things slower. If I set it to 0, is that really going to kill > > performance? I've got someone complaining that "chokolade" doesn't correct > > to "schokolade". As a someone who's highschool German faded long ago from > > my memory I'd pronounce both words the same way. > > > > Nik > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 2:11am UTC](https://discuss.elastic.co/t/question-about-phrase-suggesters-prefix-len/14016/4 "2017-07-06T02:11:26Z")
Closed on July 6, 2017, 2:11am UTC