Thanks for explaining the information. Currently I'm only using the comma-separated list of words and only using the synonym filter at query time. I find that when I set expend = true, there's quite a number of irrelevant results that came back, and this didn't happen when I set expend = false.
I've yet to try the lists of words with the symbol "=>" between them. I'm trying to solve the multi-word synonyms too, and I found that enclosing the multi-word in quotes will solve the issue. But this creates problem and the original token is not return if I enclose single word in quotes. Will using the lists of words with the symbol "=>" between them better than the comma-separated list of words to cater to the multi-word synonyms? Regards, Edwin On 8 May 2015 at 17:10, Alessandro Benedetti <benedetti.ale...@gmail.com> wrote: > Let's explain little bit better here : > First of all, the SynonimFilter is a Token Filter, and being a Token Filter > it can be part of an Analysis pipeline at Indexing and Query Time. > As the different type of analysis explicitly explains when the filtering > happens, let's go to the details of the synonyms.txt. > This file contains a set of lines, each of them describing a synonym > policy. > There are 2 different syntaxes accepted : > > > > > *couch,sofa,divanteh => thehuge,ginormous,humungous => largesmall => > tiny,teeny,weeny* > > > - A comma-separated list of words. If the token matches any of the > words, then all the words in the list are substituted, which will > include > the original token. > > > - Two comma-separated lists of words with the symbol "=>" between them. > If the token matches any word on the left, then the list on the right is > substituted. The original token will not be included unless it is also > in > the list on the right. > > > Related the "expand" param, directly from the official Solr documentation : > > expand: (optional; default: true) If true, a synonym will be expanded to > all equivalent synonyms. If false, all equivalent synonyms will be reduced > to the first in the list. > > So, starting from this definition let's answer to your questions: > > 1) Related the expand the definition seems quite clear, if anything strange > is occurring to you, let me know > 2) Related your second question, it depends on your synonym.txt file, if > you are not using the => syntax, you are going to always retrieve all > the synonyms( > included the original term) > > If you need more info let me know, it can strictly depends how you are > using the filter as well ( indexing ? querying ? both ? ) > Example : > If you are using the filter only at Indexing time, then using the => syntax > will prevent the user to search for the original token in the synonym.txt > relation. > Because it will not appear in the index. > > Cheers > > > 2015-05-08 9:24 GMT+01:00 Zheng Lin Edwin Yeo <edwinye...@gmail.com>: > > > Hi, > > > > Will like to check, for the SynonymFilterFactory, I have the following in > > my synonyms.txt: > > > > Titanium Dioxides, titanium oxide, pigment > > pigment, colour, colouring material > > > > If I set expend=false, and I search for q=pigment, I will get results > that > > matches pigment, Titanium Dioxides and titanium oxide. But it will not > > maches colour and colouring materials, as all equivalent synonyms will > only > > matches those first in the list. > > > > If I set expend=false, and I search for q=pigment, I'll get results that > > matches everything in the list (ie: Titanium Dioxides, titanium oxide, > > colour, colouring material) > > > > Is my understand correct? > > > > Also, I will like to check, how come if I search q="pigment" (enclosed in > > quotes), I only get matches for Titanium Dioxides and not pigment? > > > > Regards, > > Edwin > > > > > > -- > -------------------------- > > Benedetti Alessandro > Visiting card : http://about.me/alessandro_benedetti > > "Tyger, tyger burning bright > In the forests of the night, > What immortal hand or eye > Could frame thy fearful symmetry?" > > William Blake - Songs of Experience -1794 England >
