Hi Shubham, In other words, *you specify a large positionIncrementGap to make sure that your queries don't match across multiple values of a field*.
For example, for a query like title:"paper plate making machine", you don't want it to match with doc having two values for title:"paper plate", "making machine". A positionIncrementGap of 100 will make sure that "plate" and "making" is 100 position apart. To make you understand better, notice the positions of terms (in format token -> position) and remember that position matching matters in Lucene Query Matching: - paper -> 1 - plate -> 2 - making -> 3 - machine -> 4 Now with positionIncrementGap of 0, the doc will have these positions for title: - - paper -> 1 - plate -> 2 - making -> 3 (0+3) - machine -> 4 (0+4) which will match the query. But if we have a positionIncrementGap of 100, the doc will have these positions for title: - - paper -> 1 - plate -> 2 - making -> 103 (100+3) - machine -> 104 (100+4) which will not match the* "exact"* query due to different positions. Hope this helps. My position calculation is bit different from @erickerick...@gmail.com <erickerick...@gmail.com> as I tried to replicate the maths I could understand from the source code. Please feel free to correct if not. Anyways, the idea remains same. :) On Fri, 18 Oct 2019 at 18:36, Erick Erickson <erickerick...@gmail.com> wrote: > I really don’t understand the question. The field has to be multiValued, > but there’s no other restriction. It’s all about whether a document you > input has the same field name specified more than once, i.e. is > multiValued. That’s why the example I gave has <field name=“blah”…. twice. > > Imagine you’re indexing a document. The client side breaks up the doc on > sentence boundaries and enters them as multiple mentions of the same field, > i.e. > <doc> > <field name=“content”>sentence one</field> > <field name=“content”>sentence two</field> > <field name=“content”>sentence three</field> > <field name=“content”>sentence four</field> > <field name=“content”>sentence five</field> > </doc> > > I think you’re missing the implication that the incoming document > _already_ has the multiple fields put there by the time it gets to Solr. > > Best, > Erick > > > > On Oct 18, 2019, at 2:28 AM, Shubham Goswami <shubham.gosw...@hotwax.co> > wrote: > > > > Hi Erick > > > > Thanks for reply and your example is very helpful. > > But i think we can only use this attribute if we are getting data from a > > single field > > which has the copy of all data from every field. > > Please correct me if i am wrong. > > Thanks for your great support. > > > > Shubham > > > > On Thu, Oct 17, 2019 at 5:56 PM Erick Erickson <erickerick...@gmail.com> > > wrote: > > > >> First, it only counts if you add multiple entries for the field. > Consider > >> the following > >> <doc> > >> <field name=“blah”>a b c</field> > >> <field name=“blah”>def</field> > >> </doc> > >> > >> where the field has a positionIncrementGap of 100. The term positions of > >> the entries are > >> a:1 > >> b:2 > >> c:3 > >> d:103 > >> e:104 > >> f:105 > >> > >> Now consider the doc where there’s only one field: > >> <doc> > >> <field name=“blah”>a b c d e f</field> > >> </doc> > >> > >> The term positions are > >> a:1 > >> b:2 > >> c:3 > >> d:4 > >> e:5 > >> f:6 > >> > >> The use-case is if you, say, index individual sentences and want to > match > >> two or more words in the _same_ sentence. You can specify a phrase query > >> where the slop is < the positionIncrementGap. So in the first case, if I > >> search for “a b”~99 I’d get a match. But if I searched for “a d”~99 I > >> wouldn’t. > >> > >> Best, > >> Erick > >> > >>> On Oct 17, 2019, at 2:09 AM, Shubham Goswami < > shubham.gosw...@hotwax.co> > >> wrote: > >>> > >>> Hi Community > >>> > >>> I am a beginner in solr and i am trying to understand the working of > >>> positionIncrementGap but i am still not clear how it exactly works for > >> the > >>> phrase queries and general queires. > >>> Can somebody please help me to understand this with the help fo an > >>> example ? > >>> Any help will be appreciated. Thanks in advance. > >>> > >>> -- > >>> *Thanks & Regards* > >>> Shubham Goswami > >>> Enterprise Software Engineer > >>> *HotWax Systems* > >>> *Enterprise open source experts* > >>> cell: +91-7803886288 > >>> office: 0731-409-3684 > >>> http://www.hotwaxsystems.com > >> > >> > > > > -- > > *Thanks & Regards* > > Shubham Goswami > > Enterprise Software Engineer > > *HotWax Systems* > > *Enterprise open source experts* > > cell: +91-7803886288 > > office: 0731-409-3684 > > http://www.hotwaxsystems.com > > -- -- Regards, *Paras Lehana* [65871] Software Programmer, Auto-Suggest, IndiaMART Intermesh Ltd. 8th Floor, Tower A, Advant-Navis Business Park, Sector 142, Noida, UP, IN - 201303 Mob.: +91-9560911996 Work: 01203916600 | Extn: *8173* -- IMPORTANT: NEVER share your IndiaMART OTP/ Password with anyone.
