Thanks Mikhail! It turns out I used FlattenGraphFilter and cause the PositionLength to be all 1 and resulted in the behavior above =)
A side note is that we don't need to use WORD_SEPARATOR in the synonym file. SynonymMap.Parser.analyze would tokenize and append the separator for us. Regards, Anh Dung Bui On Mon, Jan 2, 2023 at 8:07 Mikhail Khludnev <m...@apache.org> wrote: > Hello Anh, > I was intrigued by your question. And I managed it to work somehow. > see > > https://github.com/mkhludnev/likely/blob/eval-mulyw-syns/src/test/java/org/apache/lucene/playground/TestMultiPulty.java > Beware, synonym files > > https://github.com/mkhludnev/likely/blob/eval-mulyw-syns/src/test/resources/org/apache/lucene/playground/multy-syn.txt > should use > > https://lucene.apache.org/core/8_0_0/analyzers-common/org/apache/lucene/analysis/synonym/SynonymMap.html#WORD_SEPARATOR > Have a nice hack! > > On Thu, Dec 29, 2022 at 10:00 AM Anh Dũng Bùi <dungba...@gmail.com> wrote: > > > Thanks everyone for the insight. I guess I'll use BooleanQuery then. > > > > There is also a caveat I noticed (not sure if it's an issue or not), > which > > is slightly different from the mentioned thread. When I have a multi-word > > synonym, let say "wifi router" and "internet device". Then using > > SynonymGraphFilter at query time (when building the SynonymMap I already > > escaped space with the backslash) would produce this TokenStream for a > > query of "wifi router" > > > > "wifi" (PositionIncrement=1,PositionLength=1), "internet" > > (PositionIncrement=0,PositionLength=1), "router" > > (PositionIncrement=1,PositionLength=1), "device" > > (PositionIncrement=0,PositionLength=1) > > > > This has the same effect as if I had 2 synonyms: "wifi"/"internet" and > > "router"/"device". If I convert this to a BooleanQuery it would become > > ("wifi" OR "internet") AND ("router" OR "device"), but what I would like > to > > achieve is ("wifi" AND "router") OR ("internet" AND "device") > > > > I'm curious if there would be some workaround for this case > > > > Thanks, > > Anh Dung Bui > > > > > > On Thu, Dec 29, 2022 at 4:56 AM Michael Wechner < > michael.wech...@wyona.com > > > > > wrote: > > > > > Hi Anh > > > > > > The following Stackoverflow link might help > > > > > > > > > > > > https://stackoverflow.com/questions/73240494/can-someone-assist-me-with-a-multi-word-synonym-problem-in-lucene > > > > > > The following thread seems to confirm, that escaping the space with a > > > backslash does not help > > > > > > https://lists.apache.org/list?java-user@lucene.apache.org:2022-3 > > > > > > HTH > > > > > > Michael > > > > > > > > > Am 27.12.22 um 20:22 schrieb Anh Dũng Bùi: > > > > Hi Lucene users, > > > > > > > > I recently came across SynonymQuery and found out that it only > supports > > > > single-term synonyms (since it accepts a list of Term which will be > > > > considered as synonyms). We have some multi-term synonyms like > > "internet > > > > device" <-> "wifi router" or "dns" <-> "domain name service". Am I > > right > > > > that I need to use something like a BooleanQuery for these cases? > > > > > > > > I have 2 other follow-up questions: > > > > - Does SynonymQuery have any advantage over BooleanQuery? Or is it > only > > > > different in how scores are computed? As I understand SynonymWeight > > will > > > > consider all terms as exactly the same while BooleanQuery will favor > > the > > > > documents with more matched terms. > > > > - Is it worth it to support multi-term synonyms in SynonymQuery? My > > > feeling > > > > is that it's better to just use BooleanQuery in those cases, since to > > > > support multi-term synonyms it needs to accept a list of Query, which > > > would > > > > make it behave like a BooleanQuery. Also how scoring works with > > > multi-term > > > > is another problem. > > > > > > > > Thanks & Regards! > > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > > > For additional commands, e-mail: java-user-h...@lucene.apache.org > > > > > > > > > > > -- > Sincerely yours > Mikhail Khludnev > https://t.me/MUST_SEARCH > A caveat: Cyrillic! >
